广义相对论与量子宇宙学

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[1] arXiv:2508.00951 [中文pdf, pdf, html, 其他]

标题： 施瓦茨希尔德-德西特时空在正则坐标中的宇宙时间 显示英文标题

标题： Schwarzschild-de Sitter spacetime in regular coordinates with cosmological time

Leonardo de Lima, Davi C. Rodrigues

评论： 评论：11页，3张图。代码在 https://github.com/davi-rodrigues/SdS-Cosmo-Regular

主题： 广义相对论与量子宇宙学 (gr-qc)

从施瓦茨希尔德-德西特（SdS）时空中的爱因斯坦方程出发，并在大距离处施加弗里德曼-罗伯逊-沃克坐标，我们找到了两个时间依赖度规的坐标系，这些度规在黑洞和宇宙学视界上都是平滑的。 这些坐标需要正的宇宙学常数以保持规则性，因此它们不是克鲁斯卡尔-泽克雷斯或伊萨拉坐标对德西特的扩展。 其中一种坐标系仅在1999年被发现（阿巴西坐标），并在文献中导致了相互矛盾的解释，而另一种则被简要提及并迅速被当作不物理或与SdS不兼容而被驳回。 我们推导出第二个解等价于第一个解，并且两者确实是SdS时空的等价描述。 我们还推导出了将这些坐标系与科特勒坐标和最大延伸的莱克-伊萨拉坐标联系起来的显式坐标变换。 在其他应用中，这些结果扩展了广泛使用的宇宙学和局部坐标，应该有助于进一步发展对黑洞与宇宙学背景之间精确相互作用的理解，这已成为最近一些工作的重点。 显示英文摘要

Starting from the Einstein equations in Schwarzschild-de Sitter (SdS) spacetime and imposing Friedmann-Robertson-Walker coordinates at large distances, we find two coordinate systems with time-dependent metrics that are smooth across both the black hole and cosmological horizons. These coordinates require a positive cosmological constant for regularity, and thus they are not de Sitter extensions of the Kruskal-Szekeres or Israel coordinates. One of the coordinate systems was only found in 1999 (Abbassi coordinates), and it has led to conflicting interpretations in the literature, while the other was briefly commented on and promptly dismissed as unphysical or incompatible with SdS. We derive that the second solution is equivalent to the first one, and that both are indeed equivalent descriptions of SdS spacetime. We also derive explicit coordinate transformations linking these coordinate systems to the Kottler coordinates and the maximally extended Lake-Israel coordinates. Among other applications, these results, which extend the largely used cosmological and local coordinates, should be useful for further developments in understanding the exact interplay between black holes and the cosmological background, which has been the focus of a number of recent works.

[2] arXiv:2508.00958 [中文pdf, pdf, html, 其他]

标题： 二次非度规引力中的球对称解 显示英文标题

标题： Spherically symmetric solution in quadratic non-metricity gravity

G.G.L. Nashed, Kazuharu Bamba

评论： 7页

期刊参考： 物理学期刊B 第868卷，2025年9月，139761

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

我们明确找到了二次非度规引力中的一个精确球对称解。 我们表明二次项起到宇宙学常数的作用。 这个解与文献中所有关于高阶非度规引力不存在球对称解的主张相矛盾。 此外，我们证明对于带电场方程，解可以与不带电情况相同。 这是因为场方程的非对角分量不受电荷的影响。 显示英文摘要

We explicitly find an exact spherically symmetric solution in quadratic non-metricity gravity. We show that the quadratic term acts as a cosmological constant. This solution contradicts all the claims in the literature that there is no spherically symmetric solution for higher-order non-metricity gravity. Moreover, we demonstrate that for the charged field equations, the solution can be identical to the non-charged case. This is because the off-diagonal components of the field equation do not feel the effect of the charge.

[3] arXiv:2508.01120 [中文pdf, pdf, html, 其他]

标题： 克尔-森黑洞的超辐射稳定性分析与研究 显示英文标题

标题： Analysis and research on superradiant stability of Kerr-sen Black Hole

Wen-Xiang Chen

评论： 8页

期刊参考： 世界科学研究所期刊 8.1 (2022): 193-203

主题： 广义相对论与量子宇宙学 (gr-qc)

Kerr Sen 黑洞具有伸展参数和隐藏的共形对称性。 这种黑洞的超辐射稳定性和稳态共振需要进一步研究，并构成了本研究的主要动机。 在本工作中，我们引入了一个额外的变量，称为 y，以推广之前研究的成果。 当扰动的频率处于特定范围时，即高于由自旋参数确定的某个阈值且低于角量子数乘以视界处的角速度与电荷乘以视界处的电势之和，Kerr Sen 黑洞表现出超辐射稳定性。 这种行为类似于之前在 KN 黑洞中观察到的超辐射特性。 显示英文摘要

Kerr Sen black holes possess stretchon parameters and hidden conformal symmetries. The superradiant stability and steady state resonance of such black holes warrant further investigation and form the primary motivation for this study. In this work,we introduce an additional variable, referred to as y, to generalize the findings of the previous study. When the frequency of the perturbation lies within a specific range namely, above a certain threshold determined by the spin parameter and below the sum of the azimuthal quantum number times the angular velocity at the horizon and the product of the charge with the electric potential at the horizon,the Kerr Sen black hole exhibits superradiant stability. This behavior is similar to the superradiant characteristics previously observed in KN black holes.

[4] arXiv:2508.01183 [中文pdf, pdf, html, 其他]

标题： 环量子宇宙学中包含洛伦兹项的量子 Oppenheimer-Snyder 模型 显示英文标题

标题： Quantum Oppenheimer-Snyder models in loop quantum cosmology with Lorentz term

Minyan Ou, Xiangdong Zhang

评论： 19页，18图

主题： 广义相对论与量子宇宙学 (gr-qc)

一种新的量子黑洞模型通过在量子Oppenheimer-Snyder（qOS）模型的环量子宇宙学框架中引入洛伦兹项而推导出来。 该模型具有量子修正的度规张量，代表了经典施瓦茨希尔德解的变形。 对准正常模式的研究表明，这些量子修正的黑洞在面对标量扰动时表现出稳定性。 值得注意的是，洛伦兹qOS模型中的指数衰减率相比没有该项的早期qOS模型和标准施瓦茨希尔德黑洞显著减少。 洛伦兹qOS模型的高阶共振模式也与早期qOS模型和标准施瓦茨希尔德黑洞有显著差异，表明近视界几何结构发生了实质性改变。 考虑了正负宇宙常数下的热力学性质。 对于反德西特情况，我们的分析显示，在小黑洞质量下，该环量子引力框架内的温度随着质量减小而降低，这与经典黑洞行为相反。 此外，一个对数项作为贝肯斯坦-霍金熵的主要修正项出现。 此外，LQG修正在较小半径处导致黑洞比热的额外相变。 而对于德西特情况，小黑洞的温度随着质量减小而增加，同样与经典预期不同。 类似于反德西特情况，德西特情况下的LQG修正也在小半径处导致比热的额外相变。 显示英文摘要

A novel quantum black hole model is derived by incorporating the Lorentzian term within the loop quantum cosmology framework of the quantum Oppenheimer-Snyder (qOS) model. This model features a quantum-corrected metric tensor, representing a deformation of the classical Schwarzschild solution. Investigations into the quasi-normal modes reveal that these quantum-corrected black holes exhibit stability against scalar perturbations. Notably, the exponential decay rate within the Lorentzian qOS model demonstrates a significant reduction compared to both the earlier qOS model devoid of this term and the standard Schwarzschild black hole. The higher overtones of the Lorentzian qOS model also differ significantly from those of the earlier qOS model and the standard Schwarzschild black hole, indicating that the near-horizon geometry is substantially modified. The thermodynamic properties with both positive and negative cosmological constant are considered. For the anti-de Sitter case, our analysis reveals that for small black hole masses, the temperature within this loop quantum gravity framework decreases as the mass diminishes, contrasting with classical black hole behavior. Furthermore, a logarithmic term emerges as the leading-order correction to the Bekenstein-Hawking entropy. Additionally, LQG corrections induce an extra phase transition in the black hole's heat capacity at smaller radius. While for the de Sitter case, the temperature increases as the mass decreases for small black holes, again differing from classical expectations. Similarly to the anti-de Sitter case, LQG corrections in the de Sitter case also lead to an extra phase transition in the heat capacity at small radius.

[5] arXiv:2508.01221 [中文pdf, pdf, html, 其他]

标题： 平坦空间FLRW宇宙中黑洞蒸发过程中的质量动力学 显示英文标题

标题： Masses dynamics during black hole evaporation in spatially flat FLRW universes

Ion I. Cotaescu, Ion Cotaescu Jr

评论： 9页，3图，发表后提交到aeXiv。arXiv管理员备注：与arXiv:2411.15258有大量文本重叠

主题： 广义相对论与量子宇宙学 (gr-qc)

最近得到的具有完美流体的爱因斯坦方程在FLRW渐进行为时空中的新动力学解，\cite{Cot,Cot1,Cot2}，可能描述了质量耗散到尘埃中的蒸发黑洞。 使用分析和图形方法研究了简单蒸发黑洞模型中黑洞和尘埃质量的时间演化。 显示英文摘要

The new dynamical solutions of Einstein's equations with perfect fluid in space-times with FLRW asymptotic behaviour, derived recently \cite{Cot,Cot1,Cot2}, may describe evaporating black holes whose masses dissipate into dust. The time evolution of the black hole and dust masses of simple models of evaporating black holes are studied using analytical and graphical methods.

[6] arXiv:2508.01378 [中文pdf, pdf, html, 其他]

标题： 暗能量穿越幽灵分界线的一般模型 显示英文标题

标题： A General Model for Dark Energy Crossing the Phantom Divide

Zhibang Yao, Gen Ye, Alessandra Silvestri

评论： 19页，2图

主题： 广义相对论与量子宇宙学 (gr-qc) ; 宇宙学与非星系天体物理学 (astro-ph.CO)

在空间协变理论的框架内，我们提出了一种暗能量（DE）的一般模型，其中宇宙学背景和扰动分别由不同的系数集独立控制，DE的状态方程直接由拉格朗日量中的两个时间函数决定。 这些特性允许实现任意的背景演化，同时避免线性扰动中的鬼魅和梯度不稳定性。 它们还使得可以更直接地分析虚幻穿越，而无需首先求解背景运动方程。 在这个模型中，标量模式的声音速度是尺度相关的，并在大尺度上趋于无穷大，因此在红外（IR）极限下该场变得非动态。 尽管这通常表明存在强耦合问题，但我们推测这是由于标量自由度不仅在一级近似下被冻结，在任何更高阶的IR极限下也被冻结。 鉴于这种大尺度行为特征，我们将该模型称为 \emph{冻结重力}。 在较小尺度上，标量模式以有限的声音速度传播。 当有效普朗克质量超过普朗克质量时，该理论在能量上有截断，这由声音速度中的极点所指示。 显示英文摘要

Within the framework of spatially covariant theories, we propose a general model for dark energy (DE) in which the cosmological background and perturbations are independently controlled by different sets of coefficients, and the equation of state of DE is directly determined by two free functions of time from the Lagrangian. These properties allow to realize arbitrary background evolutions while avoiding ghost and gradient instabilities in linear perturbations. They also enable a more direct analysis of phantom crossing without having to first solve the background equations of motion. In this model, the sound speed of the scalar mode is scale-dependent and approaches infinity at large scale, so that the field becomes non-dynamical in the infrared (IR) limit. Even though this usually indicates a strong coupling issue, we speculate that this is avoided because the scalar degree of freedom becomes frozen not only at linear order but also at any higher order in IR limit. Given this characteristic large scales behavior, we dub the model \emph{Freezing Gravity}. On smaller scales, the scalar mode propagates with a finite speed of sound. The theory has a cut-off in energy, signaled by the pole in the speed of sound, when the effective Planck mass exceeds Planck mass.

[7] arXiv:2508.01414 [中文pdf, pdf, html, 其他]

标题： 来自2个和3个黑洞模拟合并的引力波 显示英文标题

标题： Gravitational Waves from Simulated Mergers of 2 and 3 Black Holes

Faisal Alotaibi

主题： 广义相对论与量子宇宙学 (gr-qc)

在这个项目中，我们使用NRPy+（基于Python的数值相对论及其他领域的代码生成模块）模块和BSSN（Baumgarte-Shapiro-Shibata-Nakamura）公式，模拟两个和三个黑洞的碰撞，并提取由此产生的引力波形。 使用Brill-Lindquist初始数据和六阶有限差分法，我们使用BSSN公式演化系统，并通过Weyl标量$\psi_4$计算引力波信号。 为了评估数值误差，我们绘制了哈密顿约束，并观察到在三个黑洞碰撞中约束违反显著更高。 还检测到了意外的引力反冲，这可能会影响波形提取，这一点将留待进一步研究。 尽管受到Google Colab计算资源限制，我们成功地模拟了双黑洞系统的合并，并能够提取相应的引力波。 显示英文摘要

In this project, we simulate the collision of two and three black holes using NRPy+ (`Python-based code generation for numerical relativity and beyond') module and BSSN (Baumgarte-Shapiro-Shibata-Nakamura) formulation, and extract the resulting gravitational waveforms. Using Brill-Lindquist initial data and sixth-order finite differences, we evolve the system using the BSSN formulation and compute the gravitational-wave signal via the Weyl scalar $\psi_4$. To assess numerical error, we plot the Hamiltonian constraint and observe that constraint violations are significantly higher in the three-black-hole collision. Unexpected gravitational recoil is also detected, which may influence waveform extraction and that is left for further investigation. Despite the limitations in computational resources imposed by the Google Colab, we successfully model the merger of a binary black hole system, and we were able to extract the corresponding gravitational waves.

[8] arXiv:2508.01538 [中文pdf, pdf, html, 其他]

标题： 电磁学和引力在四维时空中的Aharonov-Bohm效应 显示英文标题

标题： Aharonov-Bohm Effects for Electromagnetism and Gravity in Four-Dimensional Spacetime

Yanhui Li, Yakefu Reyimuaji

评论： 4页，欢迎提出意见

主题： 广义相对论与量子宇宙学 (gr-qc)

本文研究了四维时空中引力阿哈罗诺夫-博姆效应的几何框架，展示了时空曲率如何在无场区域引起非局域量子相位变化。 通过在配备利维-奇维塔联络的时空流形上构建向量丛，我们推导出平行传输量子态的全纯变换。 在牛顿近似下，度规分解为闵可夫斯基背景加上标量势扰动，通过线性化爱因斯坦场方程揭示引力引起的相位变化在数学上与电磁对应物同构。 这些结果确立了引力规范结构的量子可观测性，并为通过原子干涉仪进行实验验证提供了理论支持。 显示英文摘要

This paper investigates a geometric framework for the gravitational Aharonov-Bohm effect in four-dimensional spacetime, demonstrating how spacetime curvature induces nonlocal quantum phase shifts within field-free regions. By constructing vector bundles on spacetime manifolds equipped with Levi-Civita connections, we derive the holonomy transformations for parallel-transported quantum states. Under the Newtonian approximation, metric decomposition into Minkowski background plus scalar potential perturbations reveals through the linearized Einstein field equations that the gravitationally induced phase shift is mathematically isomorphic to its electromagnetic counterpart. These results establish the quantum observability of gravitational gauge structures and provide theoretical support for experimental verification via atom interferometry.

[9] arXiv:2508.01559 [中文pdf, pdf, html, 其他]

标题： 基于广义不确定性原理引起的有效度规的统计熵 显示英文标题

标题： Statistical Entropy Based on the Generalized-Uncertainty-Principle-Induced Effective Metric

Soon-Tae Hong, Yong-Wan Kim, Young-Jai Park

评论： 14页

期刊参考： 宇宙2025，11（8），256

主题： 广义相对论与量子宇宙学 (gr-qc)

我们通过采用包含一阶和所有阶量子引力修正的有效度规，在广义不确定原理（GUP）框架下研究黑洞的统计熵。 我们构建了三种由GUP引起的有效度规，这些度规分别来源于GUP修正后的温度、熵以及所有阶GUP修正，并利用't Hooft的砖墙方法分析它们对黑洞熵的影响。 我们的结果表明，尽管有效度规及其相应的紫外截断存在差异，但当用接近视界的不变（坐标无关）距离表示时，统计熵始终满足Bekenstein-Hawking面积定律。 此外，我们证明GUP自然地规范了状态密度中的紫外发散，无需人工截断，即使仅在事件视界附近计算量子态，也能得到有限的熵。 这些发现突显了在GUP修改下面积定律的普遍性和鲁棒性，并为量子引力效应与黑洞热力学之间的相互作用提供了新的见解。 显示英文摘要

We investigate the statistical entropy of black holes within the framework of the generalized uncertainty principle (GUP) by employing effective metrics that incorporate leading-order and all-orders quantum gravitational corrections. We construct three distinct effective metrics induced by the GUP, which are derived from GUP-corrected temperature, entropy, and all-orders GUP corrections, and analyze their impact on black hole entropy using 't Hooft's brick wall method. Our results show that, despite the differences in the effective metrics and the corresponding ultraviolet cutoffs, the statistical entropy consistently satisfies the Bekenstein-Hawking area law when expressed in terms of an invariant (coordinate-independent) distance near the horizon. Furthermore, we demonstrate that the GUP naturally regularizes the ultraviolet divergence in the density of states, eliminating the need for artificial cutoffs and yielding finite entropy even when counting quantum states only in the vicinity of the event horizon. These findings highlight the universality and robustness of the area law under GUP modifications and provide new insights into the interplay between quantum gravity effects and black hole thermodynamics.

[10] arXiv:2508.01573 [中文pdf, pdf, html, 其他]

标题： 波函数坍缩在半经典引力中触发时空动力学 显示英文标题

标题： Wave Function Collapse Triggering Spacetime Dynamics in Semiclassical Gravity

Xiaoqiang Wang

主题： 广义相对论与量子宇宙学 (gr-qc)

我们提出了一种新颖的半经典机制，以统一量子力学和广义相对论，在这种机制中，处于叠加态的波函数坍缩会引发能量-动量张量的快速变化，从而触发以光速传播的时空动力学。 与假设叠加时空的模型不同，我们认为叠加会产生一个由能量-动量张量期望值驱动的单一连续经典时空。 在坍缩时，突然的变化通过爱因斯坦场方程修改时空度规，遵守因果性。 我们对此进行了研究，针对处于空间叠加态的粒子提出了详细的实验设计，并对引力扰动进行了数值模拟，解决了潜在的理论挑战，并讨论了对现有量子引力理论的影响。 该框架提供了一种无需对时空进行量子化即可调和量子和引力动力学的途径，并在未来的实验中有可测试的特征。 显示英文摘要

We propose a novel semiclassical mechanism to unify quantum mechanics and general relativity, where wave function collapse in a superposition state induces a rapid change in the energy-momentum tensor, triggering spacetime dynamics that propagate at the speed of light. Unlike models assuming superposed spacetimes, we posit that the superposition yields a single, continuous classical spacetime driven by the expectation value of the energy-momentum tensor. Upon collapse, the abrupt shift modifies the spacetime metric via Einstein's field equations, respecting causality. We explore this for a particle in a spatial superposition, propose detailed experimental designs with numerical simulations of gravitational perturbations, address potential theoretical challenges, and discuss implications for existing quantum-gravity theories. This framework offers a pathway to reconcile quantum and gravitational dynamics without quantizing spacetime, with testable signatures in future experiments.

[11] arXiv:2508.01658 [中文pdf, pdf, html, 其他]

标题： 从引力粒子产生中的几何多部分纠缠 显示英文标题

标题： Geometric multipartite entanglement from gravitational particle production

Alessio Belfiglio, Roberto Franzosi, Orlando Luongo

评论： 7页，2图

主题： 广义相对论与量子宇宙学 (gr-qc) ; 宇宙学与非星系天体物理学 (astro-ph.CO)

我们探索了在暴胀阶段引力粒子产生过程中真实多体纠缠的新生成方式。 为此，我们专注于微扰产生机制，考虑一个具有四次自耦合势的非最小耦合标量暴胀场，并计算其与背景扰动的引力相互作用产生的概率振幅。 相应的纠缠量使用最近提出的纠缠距离进行量化，该距离提供了一个\emph{粒子纠缠的几何解释，基于Fubini-Study度量}。 我们观察到，在可忽略压缩的极限下，总纠缠量由红外截断尺度主导，这与之前在双体情景中分析冯诺依曼熵的研究结果一致。 然后我们表明\emph{非可忽略的多体纠缠特征可能在暴胀期间出现，甚至在慢滚的最后阶段也是如此}，突出它们对暴胀动量尺度的依赖性。 还讨论了对非可忽略压缩、三次非高斯性、额外的观测场以及可能的观测特征的推广。 显示英文摘要

We explore novel generation of genuine multipartite entanglement within gravitational particle production processes during inflationary stages. To this end, we focus on perturbative production mechanisms, considering a non-minimally coupled scalar inflaton field with quartic self-coupling potential and computing probability amplitudes arising from its gravitational interaction with background perturbations. The corresponding entanglement amount is quantified using the recently proposed Entanglement Distance, that provides a \emph{geometric interpretation of particle entanglement, in terms of the Fubini-Study metric}. We observe that, in the limit of negligible squeezing, the total amount of entanglement is dominated by the infrared cutoff scale, in agreement with previous studies analyzing the von Neumann entropy within bipartite scenarios. We then show that \emph{non-negligible multipartite entanglement signatures may emerge across inflation, even during the latest stages of slow-roll}, highlighting their dependence on inflationary momentum scales. Generalizations to regimes with non-negligible squeezing, cubic non-Gaussianities, additional spectator fields and possible observational signatures are also discussed.

[12] arXiv:2508.01683 [中文pdf, pdf, html, 其他]

标题： 重新审视旋转黑洞中的彭罗斯过程与量子修正：对能量提取和不可约质量的影响 显示英文标题

标题： Revisiting the Penrose Process in Rotating Black Holes with Quantum Corrections: Implications for Energy Extraction and Irreducible Mass

Urooj Fatima, G. Abbas

评论： 21页，8图和3表

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

我们探索了从由量子修正参数\( \alpha \)修饰的旋转黑洞时空中提取能量。 聚焦于能层区域内的粒子分裂，我们分析了彭罗斯过程，并计算了提取效率\( \eta \)作为自转参数\( a \)和量子修正参数\( \alpha \)的函数。 我们的结果表明，增加\( \alpha \)会引起事件视界和静止极限向内移动，导致能层区域适度扩展。 这种几何变化显著增强了能量提取潜力。 通过数值求解视界方程，我们确定了最大提取效率为 11.64%。 此外，我们推导了不可约质量的表达式，强调了其在限制可提取旋转能量量方面的基础作用。 总体而言，我们的研究结果表明，量子修正对黑洞能量学有显著影响，导致与经典克尔理论预测明显偏离。 显示英文摘要

We explore the extraction of energy from a rotating black hole spacetime modified by a quantum correction parameter \( \alpha \). Focusing on particle splitting within the ergoregion, we analyze the Penrose process and compute the extraction efficiency \( \eta \) as a function of both the spin parameter \( a \) and the quantum correction parameter \( \alpha \). Our results show that increasing \( \alpha \) induces an inward shift of the event horizon and the static limit, resulting in a modest expansion of the ergoregion. This geometric change significantly enhances the energy extraction potential. By numerically solving the horizon equation, we determine a maximum extraction efficiency of 11.64\%. Additionally, we derive the expression for the irreducible mass, highlighting its fundamental role in constraining the amount of extractable rotational energy. Overall, our findings demonstrate that quantum corrections have a substantial impact on black hole energetics, leading to marked deviations from predictions based on classical Kerr theory.

[13] arXiv:2508.01732 [中文pdf, pdf, html, 其他]

标题： 赤道稳定性分析带电旋转尘埃盘内的尘埃粒子轨道 显示英文标题

标题： Equatorial stability analysis of dust particle orbits within a charged rotating disc of dust

David Rumler

评论： 8页，6图

主题： 广义相对论与量子宇宙学 (gr-qc)

尘埃粒子在带电旋转尘埃盘内的圆形轨道相对于赤道平面内的扰动的稳定性得到了分析。 在爱因斯坦-麦克斯韦理论中，带电旋转尘埃盘是一个轴对称、稳态的解，该解是通过后牛顿展开给出的。 该盘解的特点是围绕对称轴的刚性旋转以及恒定的比电荷$\epsilon$。 发现当$\epsilon<1$时，所有实现的尘埃粒子轨道都是稳定的，而当$\epsilon=1$时，所有尘埃粒子都处于临界稳定状态。 显示英文摘要

Stability of circular orbits of the dust particles within a charged rotating disc of dust with respect to perturbations in the equatorial plane is analyzed. Within Einstein-Maxwell theory, the charged rotating disc of dust is an axisymmetric, stationary solution given in terms of a post-Newtonian expansion. The disc solution is characterized by a rigid rotation around the axis of symmetry and a constant specific charge $\epsilon$. It is found that for $\epsilon<1$ all realized dust particle orbits are stable and for $\epsilon=1$ all dust particles are in marginally stable states.

[14] arXiv:2508.01770 [中文pdf, pdf, html, 其他]

标题： 类似Quintom的穿越宇宙模型在度规-仿射Myrzakulov$f(R,T,Q,T_m)$引力中 显示英文标题

标题： Quintom-like transit universe models in Metric-affine Myrzakulov $f(R,T,Q,T_m)$ gravity

Dinesh Chandra Maurya, Harjit Kumar

评论： 20页，6图

主题： 广义相对论与量子宇宙学 (gr-qc)

当前的穿越宇宙模型是称为度规-仿射Myrzakulov$f(R,T,Q,T_m)$的新类型引力理论方程的精确解 [Herko等，Phys. Dark Univ. 34 (2021) 100886]。我们发现了一个双曲解，并利用最新的观测数据确定了该模型参数的限制。我们研究了一些宇宙学因子，如减速参数$q(z)$、有效状态方程参数$\omega_{eff}$、暗能量状态方程参数$\omega_{de}$和物质能量密度参数$\Omega$随时间的变化，以帮助解释可观测宇宙的特性。我们建立了一个双曲解，并使用最新的观测数据集获得了该模型参数的观测约束。 我们研究几个宇宙学参数的演化，包括减速参数$q(z)$，有效状态方程（EoS）参数$\omega_{eff}$，暗能量状态方程参数$\omega_{de}$，以解释可观测宇宙的特性。 我们对该模型进行了 Om 诊断测试，它表示该模型的幻影情景。 暗能量状态方程参数$\omega_{de}$的行为揭示了 quintom-A 型宇宙的特征。 显示英文摘要

The current transit universe model is a precise solution to the equations of a new type of gravity theory called metric-affine Myrzakulov $f(R,T,Q,T_m)$ [Herko et al. Phys. Dark Univ. 34 (2021) 100886]. We find a hyperbolic solution and determine the limits on the model's parameters using the latest observational data. We examine how certain cosmological factors, like the deceleration parameter $q(z)$, effective equation of state parameter $\omega_{eff}$, dark energy equation of state parameter $\omega_{de}$, and matter energy density parameter $\Omega$, change over time to help explain the properties of the observable universe. We establish a hyperbolic solution and obtain the observational constraints on the model parameters using the latest observational datasets. We study the evolution of several cosmological parameters, including the deceleration parameter $q(z)$, effective equation of state (EoS) parameter $\omega_{eff}$, dark energy EoS parameter $\omega_{de}$, to explain the properties of the observable universe. We perform the Om diagnostic test for the model, and it represents the phantom scenarios of the model. The behavior of the dark energy EoS parameter $\omega_{de}$ reveals the quintom-A-type universe characteristics.

[15] arXiv:2508.01790 [中文pdf, pdf, html, 其他]

标题： 带电的Taub-NUT型黑洞在爱因斯坦-韦尔-Maxwell理论中 显示英文标题

标题： Charged Taub-NUT type Black Holes in Einstein-Weyl-Maxwell Theory

Ze Li, Hai-Shan Liu

主题： 广义相对论与量子宇宙学 (gr-qc)

我们数值构造了四维爱因斯坦-外尔-麦克斯韦理论中的新的带电Taub-NUT型黑洞解。 我们详细探讨了NUT参数和电荷参数对黑洞解的影响。 与同一理论中的静态球对称黑洞相比，有一个主要区别：存在三条NUT解分支，而静态球对称黑洞解只有两条分支。 与外尔引力中的中性NUT解不同，其中解相互交叉，我们找到的带电NUT解是不相连的。 显示英文摘要

We numerically construct new charged Taub-NUT-type black hole solutions in four-dimensional Einstein-Weyl-Maxwell theory. We explore the effects of the NUT parameter and the electric charge parameter on the black hole solutions in great detail. Compared with static spherical black holes in the same theory, there is one major difference: there are three branches of NUT solutions, whereas there are only two branches of static spherical black hole solutions. Compared with neutral NUT solutions in Weyl gravity, where the solutions intersect with each other, the charged NUT solutions we find are disconnected.

[16] arXiv:2508.01803 [中文pdf, pdf, html, 其他]

标题： 时间作为宇宙学现象 显示英文标题

标题： Time as a Cosmological Phenomenon

Andrea Palessandro

评论： 25页，5图

主题： 广义相对论与量子宇宙学 (gr-qc) ; 物理的历史与哲学 (physics.hist-ph)

我们证明时间之箭与整个宇宙的几何和拓扑密切相关，因此最好将其理解为一种宇宙学现象。 显示英文摘要

We show that the arrow of time is intimately related to the geometry and topology of the whole universe, and is therefore best understood as a cosmological phenomenon.

[17] arXiv:2508.01820 [中文pdf, pdf, html, 其他]

标题： 不可接触的裸奇点时空结构 显示英文标题

标题： The space-time structure of an untouchable naked singularity

Leonel Bixano, Tonatiuh Matos

评论： 2个图

主题： 广义相对论与量子宇宙学 (gr-qc)

根据宇宙审查猜想，裸奇点在自然界中被认为是被禁止的，必须被视界隐藏起来。 在本工作中，我们展示了爱因斯坦-麦克斯韦-稀释子方程的一个精确解的因果结构，该解表示一个虫洞（WH），其中环形奇点没有任何视界，是无法触及的，即与宇宙的其余部分在因果上断开连接。 我们分析了其度规函数在Papapetrou坐标中的表现，以验证时空中的度规解析性，构建了Carter-Penrose图，并使用Boyer-Linquist坐标来可视化环形奇点由喉部所包围的情况。 我们得出结论，该虫洞中的环形奇点由喉部包围，类似于Kerr-Newman黑洞中的事件视界包围环形奇点，从而满足虫洞宇宙审查猜想。 在本工作中，我们表明虫洞的拓扑结构使得喉部两侧被奇点分隔，但它们在拓扑上是相同的，从而在这两个区域之间产生一种瞬时的连接。 显示英文摘要

According to the Cosmic Censorship conjecture, naked singularities are thought to be forbidden in nature and must remain hidden by a horizon. In this work, we present the causal structure of an exact solution to the Einstein-Maxwell-Dilaton equations representing a wormhole (WH), where the ring singularity, without even horizon, is untouchable, this is, causally disconnected from the rest of the universe. We analyze its metric functions in Papapetrou coordinates to verify metric analyticity in spacetime, construct the Carter-Penrose diagram, and use Boyer-Linquist coordinates to visualize the lining of the ring singularity by the throat. We conclude that the ring singularity in this WH is lined by the throat, similar to how the event horizon lines the ring singularity in the Kerr-Newman black hole, satisfying the Wormhole Cosmic Censorship Conjecture. In this work we show that the topology of the WH is such that the two sides of the throat are separated by the singularity, but are topologically identified, giving rise to an instantaneous connection between these two regions.

[18] arXiv:2508.01827 [中文pdf, pdf, html, 其他]

标题： 棉和共形 Killing 理论中的广义 Vaidya 时空 显示英文标题

标题： Generalized Vaidya Spacetime in Cotton and Conformal Killing Theories

Metin Gürses, Yaghoub Heydarzade, Çetin Şentürk

评论： 13页

主题： 广义相对论与量子宇宙学 (gr-qc)

我们证明了Cotton引力和共形Killing引力的非真空场方程接受一种广义的Vaidya型解。特别是，除了与物质源相关的标准诱导项外，广义度规还包含两个额外的校正项，这些项纯粹源于这些理论的独特结构。这种扩展解推广了广义相对论中的经典Vaidya时空，并为这些三阶引力理论框架内辐射时空的动力学提供了新的见解。 显示英文摘要

We demonstrate that the non-vacuum field equations of Cotton gravity and Conformal Killing gravity admit a generalized class of Vaidya-type solutions. In particular, beyond the standard induced term associated with the matter source, the generalized metric incorporates two additional correction terms of purely geometric origin, arising from the unique structure of these theories. This extended solution generalizes the classical Vaidya spacetime in General Relativity and offers new insights into the dynamics of radiating spacetimes within the framework of these third-rank gravity theories.

[19] arXiv:2508.01830 [中文pdf, pdf, html, 其他]

标题： 黑洞化学：最初的15年 显示英文标题

标题： Black Hole Chemistry: the first 15 years

Robert B. Mann

评论： 105页，24幅图，LaTeX；为《广义相对论110周年专刊》撰写的邀请综述，编辑W.T. Ni

期刊参考： 《现代物理学期刊 D34》（2025）2542001

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

热力学引入引力物理始于50年前，当时发现一旦考虑半经典量子效应，黑洞的行为就像热力学系统。 引入引力物理并最初应用于黑洞的温度、熵、功和相变概念，后来也被扩展到宇宙视界和其他情况。 15年前出现了一个重大进展，即以宇宙学常数的形式引入压强。 通过将热力学相空间扩展以包含这一项及其共轭体积，发现黑洞表现出多种相变，这些相变类似于化学实验室中观察到的现象。 黑洞热力学已发展为黑洞化学，这为理解黑洞的本质提供了丰富的见解，引入了如范德华流体、再入相变和三相点等概念。 我将讨论黑洞化学的起源及其在早期综述[1]中涵盖的基本特征，然后描述此后该领域的发展。 例子包括多临界行为、聚合物转变、超流转变、标量毛发、热机、NUT电荷、加速热力学、焦耳-汤姆逊膨胀、全息理论、复杂性、中心荷临界性、微观结构、热力学张力、相动力学和热力学拓扑。 这些新现象的丰富性表明，我们很可能仍从黑洞化学中学到很多。 显示英文摘要

The introduction of thermodynamics into gravitational physics began 5 decades ago with the discovery that black holes behave like thermodynamic systems once semiclassical quantum effects are taken into account. Notions of temperature, entropy, work, and phase changes that were introduced into gravitational physics and originally applied to black holes, were later extended to cosmological horizons and other settings as well. A major development occurred 15 years ago with the introduction of pressure in the form of a cosmological constant. By extending the thermodynamic phase space to include this term, along with its conjugate volume, black holes were found to exhibit a broad variety of phase transitions that resembled phenomena seen in chemistry labs. Black hole thermodynamics has become Black Hole Chemistry, which has led to a wealth of insights into the nature of black holes, introducing concepts such as Van der Waals fluids, reentrant phase transitions, and triple points into gravitational physics. I discuss the origins of Black Hole Chemistry and its basic features covered in an earlier review [1], and then go on to describe developments in the subject that have taken place since then. Examples include multicritical behaviour, polymeric transitions, superfluid transitions, scalar hair, heat engines, NUT-charge, acceleration thermodynamics, the Joule-Thompson expansion, holography, complexity, central charge criticality, microstructure, thermodynamic tension, phase dynamics, and thermodynamic topology. This wealth of new phenomena suggest that we likely still have a lot to learn from Black Hole Chemistry.

[20] arXiv:2508.01876 [中文pdf, pdf, html, 其他]

标题： 标量场-物质相互作用模型在各向异性宇宙中的平均动力学：局部旋转对称的 Bianchi I 宇宙时空 显示英文标题

标题： Averaging Dynamics of Scalar Field-Matter Interacting Models in Anisotropic Universes: The Locally Rotationally Symmetric Bianchi I Spacetime

Alfredo D. Millano, Genly Leon, Andronikos Paliathanasis

评论： 59页，47个化合物图

主题： 广义相对论与量子宇宙学 (gr-qc) ; 数学物理 (math-ph)

我们考虑一个各向异性宇宙学模型，该模型基于局部旋转的Bianchi I时空，结合了标量场和非零的宇宙相互作用项。采用平均值理论框架来研究相关的非线性微分方程。通过对引力场方程进行定性分析，我们获得了关于各向异性标量场模型与广义谐波势解空间结构的重要见解。标量场与物质之间的相互作用由一个依赖于哈勃参数、标量场的时间导数以及冷暗物质和暗能量的能量密度的一般表达式描述。这种表述涉及调节相互作用的真实参数，以及一个具有哈勃参数维度的耦合常数。我们证明哈勃参数作为时间依赖的扰动参数，控制完整系统与其时间平均对应物之间的差异。当此参数减小时，两个系统都趋同到相同的渐近行为。这使得振荡效应得以抑制，显著简化了动力学分析。最后，我们确定了相互作用参数的条件，通过防止奇点的出现来确保系统演化的正则性。 显示英文摘要

We consider an anisotropic cosmological model based on the locally rotational Bianchi I spacetime, incorporating a scalar field and a non-zero cosmological interaction term. The framework of averaging theory is employed to study the associated non-linear differential equations. Through a qualitative analysis of the gravitational field equations, we obtain valuable insights into the structure of the solution space for the anisotropic scalar field model with a generalized harmonic potential. The interaction between the scalar field and matter is described by a general expression that depends on the Hubble parameter, the time derivative of the scalar field, and the energy densities of cold dark matter and dark energy. This formulation involves real parameters that modulate the interaction, as well as a coupling constant with the dimensions of the Hubble parameter. We show that the Hubble parameter serves as a time-dependent perturbation parameter, controlling the discrepancy between the full system and its time-averaged counterpart. As this parameter decreases, both systems converge to the same asymptotic behaviour. This enables the suppression of oscillatory effects, significantly simplifying the dynamical analysis. Finally, we identify conditions on the interaction parameters that ensure the regularity of the system's evolution by preventing the emergence of singularities.

[21] arXiv:2508.02100 [中文pdf, pdf, html, 其他]

标题： 从坍缩物质通过量子隧穿形成冻结星 显示英文标题

标题： Formation of Frozen Stars from collapsing matter by tunneling

Ram Brustein, A.J.M. Medved, Tamar Simhon

主题： 广义相对论与量子宇宙学 (gr-qc)

冻结星是一种黑洞模仿者：一种超致密物体，其外部几何结构类似于广义相对论黑洞，但在物质组成和内部几何的正则性方面有所不同。 它由球对称的开弦通量管集合产生，这些通量管具有极强各向异性的能量-动量-应力张量，具有最大负径向压强。 冻结星是对高度量子化、闭弦聚合物模型的有效经典描述。 任何黑洞模仿者模型的一个关键挑战是解释这样的物体如何从物质坍缩体中形成。 我们在之前的一篇文章中开始解决这个重要问题，通过适应Gibbons和Hawking的欧几里得作用量方法，表明进入冻结星的转变很可能是可能的。 在这里，我们通过显示物质坍缩壳量子隧穿进入冻结星的转变概率为1（忽略不计的修正除外）来改进我们之前的结果。 我们的结论是，因此这种转变是不可避免的。 显示英文摘要

The frozen star is a type of black hole mimicker: An ultracompact object whose exterior geometry resembles that of a general-relativistic black hole but differs in its matter composition and in the regularity of its interior geometry. It is sourced by a spherically symmetric collection of open-string flux tubes, which posses an extremely anisotropic energy-momentum-stress tensor with maximally negative radial pressure. The frozen star represents an effective classical description of the highly quantum, closed-string polymer model. A key challenge for any model of a black hole mimicker is to explain how such objects can form from a collapsing body of matter. We started to address this important problem in a previous article by adapting the Euclidean-action method of Gibbons and Hawking to show that the transition into a frozen star is likely. Here, we improve on our previous results by showing that the transition probability for a collapsing shell of matter to tunnel quantum mechanically into a frozen star is unity, up to negligible corrections. Our conclusion is that such a transition is therefore inevitable.

[22] arXiv:2508.02156 [中文pdf, pdf, html, 其他]

标题： 球对称静态解在物质-曲率耦合存在下的情况 显示英文标题

标题： Spherically Symmetric, Static Solutions in Presence of Matter-Curvature Coupling

Debanjan Debnath, Kaushik Bhattacharya

评论： 33页，3图

主题： 广义相对论与量子宇宙学 (gr-qc)

在本工作中，我们提出了引力理论中一些球对称、静态的时空，在该理论中允许时空曲率与流体变量之间的非最小耦合（NMC）。 结果显示，这些非最小耦合理论可能容纳新的度规解类别。 从广义相对论中已知的度规解也可以是非最小耦合理论的解，在这些情况下，NMC会影响源时空的流体性质。 本文介绍了多种解决非最小耦合理论中出现的修正场方程的方法。 NMC产生了应力-能量张量的多种定义。 本文讨论了与这些曲率来源相关的复杂性，因为与最小耦合的广义相对论不同，在目前的理论中，里奇曲率本身可以影响种子时空曲率的有效流体的应力-能量张量。 本文给出了与各种可能的应力-能量张量形式相关的各种能量条件。 显示英文摘要

In this work we have proposed some spherically symmetric, static spacetimes in a theory of gravity which permits non-minimal coupling (NMC) between curvature of spacetime and fluid variables. It is shown that these non-minimally coupled theories may admit of new class of metric solutions. Known metric solutions from GR can also be solutions of the non-minimally coupled theories, for these cases the NMC affects the nature of the fluid which sources the spacetime. The paper presents multiple ways in which the modified field equations appearing in non-minimally coupled theories can be solved. The NMC produces multiple definitions of the stress-energy tensor. The paper discusses the complexity related to these sources of curvature as, unlike in minimally coupled general relativity, in the present theory the Ricci curvature itself can affect the stress-energy tensor of the effective fluid which seeds spacetime curvature. The various energy conditions related to various forms of possible stress-energy tensors are presented in the paper.

[23] arXiv:2508.02213 [中文pdf, pdf, html, 其他]

标题： 黑洞准周期振荡对与NED耦合的f(R,T)引力的观测约束 显示英文标题

标题： Observational Constraints on f(R,T) gravity coupled with NED from Black Hole Quasi Periodic Oscillations

Bidyut Hazarika, Abhishek Baruah, Prabwal Phukon

评论： 20页，30图

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

在本工作中，我们研究非线性电动力学（NED）和$f(R,T)$引力对磁荷黑洞周围准周期振荡（QPOs）的影响。通过分析圆轨道的有效势、特定能量和角动量，我们研究NED参数$\alpha$和引力耦合参数$\beta$如何影响轨道动力学。增加$\alpha$会导致与Reissner Nordstrom行为的系统性偏离，体现在ISCO半径和轨道频率的变化上。我们进一步利用相对论进动（RP）、扭曲盘（WD）和摄动共振（ER2-ER4）模型探讨QPO生成半径。我们进一步通过使用来自跨越广泛质量尺度的黑洞的QPO数据进行基于MCMC的参数估计来扩展我们的分析。这种方法对模型参数产生了一致的观测约束。 显示英文摘要

In this work, we examine the influence of nonlinear electrodynamics (NED) and $f(R,T)$ gravity on quasi-periodic oscillations (QPOs) around a magnetically charged black hole. By analyzing the effective potential, specific energy, and angular momentum of circular orbits, we study how the NED parameter $\alpha$ and the gravitational coupling parameter $\beta$ affect orbital dynamics. Increasing $\alpha$ leads to systematic deviations from the Reissner Nordstrom behavior, reflected in shifts in the ISCO radius and orbital frequencies. We further explore QPO-generating radii using the Relativistic Precession (RP), Warped Disk (WD), and Epicyclic Resonance (ER2-ER4) models. We further extend our analysis by performing an MCMC-based parameter estimation using QPO data from black holes spanning a wide range of mass scales. This approach yields consistent observational constraints on the model parameters.

[24] arXiv:2508.02315 [中文pdf, pdf, html, 其他]

标题： 一般静态和轴对称时空中的自旋进动 显示英文标题

标题： Spin precession in general stationary and axisymmetric spacetimes

Shaofei Xu, Junji Jia

评论： 22页，3图和1表

主题： 广义相对论与量子宇宙学 (gr-qc)

本文研究了利用Mathisson-Papapetrou-Dixon方程在一般静态和轴对称时空的赤道平面上运动的测试粒子的自旋进动。 通过不同的近似方法，推导了两种情况下的自旋进动角度，即小自旋情况和自旋轨道平面平行情况。 对于小自旋情况，沿圆轨道的赤道平面上的自旋分量的进动角度被找到，而垂直分量被证明是一个守恒量。 对于自旋轨道平面平行的情况，一般情况下轨道运动和自旋运动通常互不影响，自旋进动角度使用后牛顿方法计算到轨道半通径p的任意高阶。 在Kerr-Newman时空中，对这两种情况的进动角度进行了定性和定量分析，以阐明其特征。 对于大轨道半径，显示进动角度级数的主导项通常与时空质量成正比，而Lense-Thirring效应总是从次主导项出现。 然后将这些进动结果应用于各种天体物理系统，以确定它们的自旋进动速率。 对于有观测数据的系统，我们的结果显示出极好的一致性。 对于没有观测数据的系统，我们在主导项和Lense-Thirring效应项上预测了它们的自旋进动速率。 这些预测表明，木星的卫星表现出异常大的测地自旋进动，其Lense-Thirring效应可能用现有技术检测到。 显示英文摘要

This paper investigates the spin precession of test particles moving in the equatorial plane of general stationary and axisymmetric spacetimes using the Mathisson-Papapetrou-Dixon equations. The spin precession angles for two cases, the small-spin case and the spin-orbital plane parallel case, are derived using different approximations. For the small-spin case, the precession angle of the spin components in the equatorial plane along circular orbits is found, and perpendicular component is shown to be a constant of motion. For the spin-orbital plane parallel case, it is shown that in general the orbital and spin motions generally do not affect each other, and the spin precession angle is calculated using the post-Newtonian method to an arbitrarily high order of the orbital semi-latus rectum p. The precession angles in both cases are analyzed both qualitatively and quantitatively in the Kerr-Newman spacetime to elucidate their features. For large orbital radii, it is shown that the leading order of the precession angle series is generally proportional to the spacetime mass while the Lense-Thirring effect always appears from the subleading order. These precession results are then applied to various astronomical systems to determine their spin precession rates. For systems with observational data, our results show excellent agreement. For systems without observational data, we predict their spin precession rates at both the leading and Lense-Thirring effect orders. These predictions indicate that Jupiter's satellites exhibit exceptionally large geodetic spin precession and their Lense-Thirring effect may be detectable with current technology.

[25] arXiv:2508.02346 [中文pdf, pdf, html, 其他]

标题： 可观测量是局部的 显示英文标题

标题： Observables are glocal

Emil Broukal, Andrea Di Biagio, Eugenio Bianchi, Marios Christodoulou

主题： 广义相对论与量子宇宙学 (gr-qc) ; 量子物理 (quant-ph)

我们研究在有限图上定义的背景无关理论中可观测量问题是如何完全解决的。 我们认为坐标独立性的正确类比是图标签变化下的不变性，这是一种排列不变性。 通过群平均形成的不变量探测整个图——它们是全局的。 引人注目的是，可以构造出完整的可观测量集合，每个都寻找一个连通子图结构——局部相关性。 通过全局和局部图概念之间微妙的相互作用，几何信息完全编码在背景无关的可观测量中，我们称这种行为为glocal。 这为离散广义相对论提供了物理上有意义的完整可观测量集合，暗示了环量子引力自旋网络状态空间的重新表述，并揭示了可观测量问题与图同构问题之间的深刻联系。 显示英文摘要

We study how the problem of observables is fully resolved for background independent theories defined on finite graphs. We argue the correct analogue of coordinate independence is the invariance under changes of graph labels, a kind of permutation invariance. Invariants are formed by a group average that probes the entire graph -- they are global. Strikingly, sets of complete observables can be constructed so that each seeks a connected subgraph structure -- local correlations. Geometrical information is fully encoded in background independent observables through this subtle interplay of global and local graph notions, a behavior we term glocal. This provides physically meaningful complete sets of observables for discrete general relativity, suggests a reformulation of the spin networks state space of loop quantum gravity, and reveals deep connections between the problem of observables and the graph isomorphism problem.

[26] arXiv:2508.02355 [中文pdf, pdf, html, 其他]

标题： 通过干涉特征探索具有多个光子球的黑洞 显示英文标题

标题： Exploring black holes with multiple photon spheres by interferometric signatures

Xi-Jing Wang, Yuan Meng, Xiao-Mei Kuang, Kai Liao

评论： 14页，4图

主题： 广义相对论与量子宇宙学 (gr-qc)

在本文中，我们研究了具有单个或双光子球的毛发施瓦茨希尔德黑洞（hSBHs）的干涉特征。我们的兴趣主要源于两个考虑：（i）黑洞图像中的光子环结构在长基线上产生强而通用的干涉特征，从而可以精确测量黑洞参数并检验引力理论；（ii）hSBH描述了由额外源引起的标准施瓦茨希尔德黑洞（SBH）的变形，在某些参数范围内它们可以具有双光子球。 通过分析和数值方法，我们发现对于具有单个光子球的hSBH，图像的复数可见度振幅表现出阻尼振荡。当内光子球的有效势能低于外光子球时，双光子球情况下会出现类似行为，因为靠近内光子球的光子会被引力捕获。然而，当内势能更高时，会出现拍频图案。 我们的发现表明，复数可见度振幅可以编码中心黑洞光子球结构的特征。 显示英文摘要

In this paper, we investigate the interferometric signatures of hairy Schwarzschild black holes (hSBHs) that have either single or double photon spheres. Our interest mainly stems from two considerations: (i) the photon ring structure in black hole images produces strong and universal interferometric signatures on long baselines, enabling precision measurements of black hole parameters and testing gravitational theory; (ii) the hSBH describes the deformation of standard Schwarzschild black hole (SBH) induced by additional sources, and they can feature double photon spheres within certain parameter regimes. Using both analytical and numerical methods, we find that for a hSBH with a single photon sphere, the complex visibility amplitude of the image exhibits damped oscillations. A similar behavior appears in the double photon sphere case when the inner photon sphere has lower effective potential than the outer one, as the photons near the inner photon sphere remain trapped by gravity. However, when the inner potential is higher, a beat pattern rises. Our findings reveal that the complex visibility amplitude can encode the signature of the photon sphere structure of the central black hole.

[27] arXiv:2508.02396 [中文pdf, pdf, html, 其他]

标题： 宇宙学模型在非最小标量非度规引力中的动力学分析 显示英文标题

标题： Dynamical analysis of cosmological models in non-minimal scalar non-metricity gravity

Bikash Chandra Roy, Bikash Chandra Paul

主题： 广义相对论与量子宇宙学 (gr-qc)

我们研究了在标量非度规理论框架下空间平坦的弗里德曼-罗伯逊-沃尔克（FRW）宇宙的演化。在该模型中，我们考虑由标量场描述的暗物质（DM）和暗能量（DE）。在本文中，我们考察了观测宇宙演化的渐近行为。我们通过在非度规理论中包含标量场的有效能量密度来探测宇宙，该理论描述了DE，并考虑了DM与有效能量密度之间的相互作用。确定了自治系统的临界点及其稳定性，以了解宇宙的行为。对于给定的一组参数，宇宙学模型能够容纳宇宙的晚期加速阶段，还发现了一个物质主导的鞍点，随后是由类似刚性流体的DE主导的减速阶段。我们获得了一类新的宇宙学模型，该模型容纳早期暴胀、物质主导时期以及未来减速阶段，随后是宇宙的晚期加速。 显示英文摘要

We investigate the evolution of a spatially flat Friedmann-Robertson-Walker (FRW) universe in the framework of scalar non-metricity theory of gravity. In the model, we consider dark matter (DM) and dark energy (DE) described by the scalar field. In the paper, we examine the asymptotic behavior of the evolution of the observed universe. We probe the universe with and without an interaction between DM and the effective energy density including scalar field in the non-metricity theory that describes the DE. The critical points of the autonomous system and their stability are determined to understand the behaviour of the universe. The cosmological models accommodate the late accelerating phase of the universe for a given set of parameters, a matter-dominated saddle point is also found to exist which is flowed by a decelerating phase dominated by stiff fluid like DE. We obtain a new class of cosmological model accommodating early inflation, matter-dominated era, and a future decelerating phase followed by late acceleration of the universe.

[28] arXiv:2508.02406 [中文pdf, pdf, html, 其他]

标题： 可穿越的虫洞在非最小爱因斯坦-杨-米尔斯引力中：几何、能量条件和引力透镜效应 显示英文标题

标题： Traversable Wormholes in non-minimal Einstein-Yang-Mills Gravity: Geometry, Energy Conditions, and Gravitational Lensing

Jureeporn Yuennan, Allah Ditta, Thammarong Eadkhong, Phongpichit Channuie

评论： v1：14页，15图

主题： 广义相对论与量子宇宙学 (gr-qc)

本研究在非最小爱因斯坦-杨-米尔斯（EYM）引力框架内，提出了一类新的静态、球对称的可穿越虫洞解，其中杨-米尔斯场为纯磁场，并由SU(2)规范对称性支配。通过引入非零红移函数以及里奇标量与杨-米尔斯场强度张量之间的直接耦合，该工作研究了非最小耦合常数$\xi$和磁荷$Q$对虫洞几何结构的影响。分析表明，适当选择这些参数可以满足flare-out和喉部条件，从而在不需要奇异物质的情况下构造出物理上可行的可穿越虫洞。该研究进一步评估了阿诺维特-德塞尔-米斯纳（ADM）质量，显示通过欧拉-海森堡型贡献建模的量子修正会减少总引力质量，并可能稳定结构。能量条件被分析，揭示了在虫洞喉部附近存在局部的零能条件和弱能条件的违反，而强能条件仍然得到满足。此外，在虫洞存在的情况下计算了光线偏折，表明存在正的偏折角度，并确认了引力场的整体吸引力。这些发现突显了非最小规范-引力耦合在构建可观测可区分的虫洞构型中的作用。 显示英文摘要

This study presents a new class of static, spherically symmetric traversable wormhole solutions within the framework of non-minimal Einstein-Yang-Mills (EYM) gravity, where the Yang-Mills field is purely magnetic and governed by the SU(2) gauge symmetry. By incorporating a non-zero redshift function and a direct coupling between the Ricci scalar and the Yang-Mills field strength tensor, the work examines the influence of the non-minimal coupling constant $\xi$ and the magnetic charge $Q$ on the wormhole geometry. The analysis demonstrates that suitable choices of these parameters can satisfy the flare-out and throat conditions, allowing for physically viable traversable wormholes without requiring exotic matter. The study further evaluates the Arnowitt-Deser-Misner (ADM) mass, showing that quantum corrections, which are modeled through Euler-Heisenberg-type contributions, reduce the total gravitational mass and may stabilize the structure. The energy conditions are analyzed, revealing localized violations of the null and weak energy conditions at the wormhole throat, while the strong energy condition remains satisfied. Additionally, light deflection in the presence of the wormhole is calculated, indicating positive deflection angles and confirming the overall attractive nature of the gravitational field. These findings highlight the role of non-minimal gauge-gravity couplings in constructing observationally distinguishable wormhole configurations.

[29] arXiv:2508.02466 [中文pdf, pdf, html, 其他]

标题： 存在辅助标量场的具有两个自由度的空间协变引力：哈密顿分析 显示英文标题

标题： Spatially covariant gravity with two degrees of freedom in the presence of an auxiliary scalar field: Hamiltonian analysis

Jun-Cheng Zhu, Shu-Yu Li, Xian Gao

评论： 21页，无图

主题： 广义相对论与量子宇宙学 (gr-qc)

研究了一类尊重空间协变性并在存在仅含空间导数的非动力学辅助标量场的引力理论。 通常，在度规部分没有高阶时间导数的情况下，由于一般协变性的破坏，会有3个自由度（DOFs）传播。 通过哈密顿约束分析，我们检查了消除标量DOF的条件，使得只有2个DOFs传播，这对应于均匀各向同性背景中的张量引力波。 我们发现需要两个条件，每个条件都可以消除半个自由度。 根据其对狄拉克矩阵的影响，第二个条件可以进一步分为两种情况。 我们还将这些形式条件应用于多项式类型的拉格朗日量作为具体例子，其中所有单项式都是包含两个导数的空间协变标量。 我们的结果与基于微扰方法的先前分析一致。 显示英文摘要

A class of gravity theories respecting spatial covariance and in the presence of non-dynamical auxiliary scalar fields with only spatial derivatives is investigated. Generally, without higher temporal derivatives in the metric sector, there are 3 degrees of freedom (DOFs) propagating due to the breaking of general covariance. Through a Hamiltonian constraint analysis, we examine the conditions to eliminate the scalar DOF such that only 2 DOFs, which correspond the tensorial gravitational waves in a homogeneous and isotropic background, are propagating. We find that two conditions are needed, each of which can eliminate half degree of freedom. The second condition can be further classified into two cases according to its effect on the Dirac matrix. We also apply the formal conditions to a polynomial-type Lagrangian as a concrete example, in which all the monomials are spatially covariant scalars containing two derivatives. Our results are consistent with the previous analysis based on the perturbative method.

[30] arXiv:2508.02603 [中文pdf, pdf, html, 其他]

标题： 共形 Killing 引力中宇宙学参数和CMB第一声学峰的约束 显示英文标题

标题： Constraints on cosmological parameters and CMB first acoustic peak in conformal Killing gravity

Salvatore Capozziello, Carlo Alberto Mantica, Luca Guido Molinari, Giuseppe Sarracino

评论： 10页，4图，3表

主题： 广义相对论与量子宇宙学 (gr-qc)

在共形Killing引力宇宙学的框架下，我们对两种不同的重子声学振荡数据集（DESI和SDSS DR16）以及两种超新星Ia数据集（Pantheon+和Union3）进行了贝叶斯分析。 在空间平坦的FRW背景中，H0和Omega_M的结果与Lambda-CDM情景一致。 我们得到暗区的新密度Omega_D具有不可忽略的负值，并且其在宇宙学观测量演化中的相关性因此定量地找到了其在真实数据中对匹配标准情景的贡献。 结果确认了暗能量的动力学特性。 我们还计算了减速参数q0和当前时间暗能量状态方程参数w0：后者属于第五元素区域。 对CMB第一声学峰的评估使其非常接近普朗克合作组提供的最佳值。 在这种情景下，我们可以得出结论，晚期和早期数据可以在相同的标准下成功匹配。 显示英文摘要

In the frame of conformal Killing gravity cosmology, we performed a Bayesian analysis on two different datasets of Baryonic Acoustic oscillations (DESI and SDSS DR16) and on two datasets of SNeIa (Pantheon+ and Union3). The results for H0 and Omega_M in a spatially flat FRW background are consistent with the Lambda-CDM scenario. We obtain a non-negligible negative value for the novel density of dark sector, Omega_D, and its relevance in the evolution of the cosmological observables thus finding quantitatively what its contribution is on real data to match the standard scenario. The results confirm the dynamical character of dark energy. We also calculate the deceleration parameter q0 and the present time dark energy equation of state parameter w0: the latter belongs to the quintessence regime. The evaluation of the first acoustic peak of CMB places it extraordinarily near to the best value provided by the Planck collaboration. In this scenario, we can conclude that late time and early time data can be successfully matched under the same standard.

交叉提交 (展示 19 之 19 条目 )

[31] arXiv:2507.21215 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]

标题： 超冷相变后的再加热与辐射对称性破缺 显示英文标题

标题： Reheating after the Supercooled Phase Transitions with Radiative Symmetry Breaking

Francesco Rescigno, Alberto Salvio

评论： 28页，3图

主题： 高能物理 - 现象学 (hep-ph) ; 宇宙学与非星系天体物理学 (astro-ph.CO) ; 高能物理 - 理论 (hep-th)

具有辐射对称性破缺（RSB）的理论会导致一阶相变，并在超冷却时期持续足够长的情况下产生引力波以及原初黑洞。 在这里，我们解释如何在上述这类理论中的该时期之后有效加热宇宙。 有两种可能的情况，取决于RSB尺度是否远大于电弱（EW）对称性破缺尺度。 当它是时，主要的再加热机制可以是标准模型（SM）领域中负责RSB的场的衰变。 我们指出，以类似的方式可以产生暗物质（DM），并且我们详细分析了惰性中微子的情况，发现当这种粒子处于$10^2$MeV尺度时，在一个合理的SM完成中可以再现全部的DM丰度。 当RSB尺度并不远大于电弱对称性破缺尺度时，我们发现当真空能密度首先完全转移到暗光子，然后通过暗光子衰变转移到SM费米子时，总是会发生有效的再加热。 显示英文摘要

Theories with radiative symmetry breaking (RSB) lead to first-order phase transitions and the production of gravitational waves as well as primordial black holes if the supercooling period lasted long enough. Here we explain how to efficiently reheat the universe after such period in the above-mentioned class of theories. Two cases are possible, depending on whether the RSB scale is much larger than the electroweak (EW) symmetry breaking scale or not. When it is, the dominant reheating mechanism can be the decays of the field responsible for RSB in the Standard Model (SM) sector. We point out that in a similar way dark matter (DM) can be produced and we analyze in some detail the case of a sterile-neutrino, finding that the full DM abundance is reproduced when this particle is at the $10^2$ MeV scale in a well-motivated SM completion. When the RSB scale is not much larger than the EW symmetry breaking scale, we find that efficient reheating always occurs when the energy density of the false vacuum is first entirely transferred to a dark photon and then to SM fermions via dark-photon decays.

[32] arXiv:2507.22970 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 关于广义维数中伽利略子的AdS/CFT等价变换的注记 显示英文标题

标题： A Note on the AdS/CFT Equivalence Transformation for Galileons in General Dimensions

Kurt Hinterbichler, Samanta Saha

评论： 13页

主题： 高能物理 - 理论 (hep-th)

AdS/CFT等价变换是一种场重定义，它将破坏共形对称性的Weyl标量和AdS膜实现联系起来。 作用于具有二阶运动方程的理论，它将共形伽利略子映射到探测AdS背景的平坦膜上的DBI伽利略子。 在这里，我们将此映射扩展到任意维度，并解决了关于奇数维中Wess-Zumino项的一个明显谜题。 显示英文摘要

The AdS/CFT equivalence transformation is a field redefinition that relates the Weyl dilaton and AdS brane realizations of broken conformal symmetry. Acting on theories with second order equations of motion, it maps the conformal galileons to the DBI galileons for a flat brane probing an AdS bulk. Here we extend this map to arbitrary dimensions and resolve an apparent puzzle regarding the Wess-Zumino terms in odd dimensions.

[33] arXiv:2508.00997 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 世界线量子场论中的隧穿振幅和霍金辐射 显示英文标题

标题： Tunnelling amplitudes and Hawking radiation from worldline QFT

Anton Ilderton, Karthik Rajeev

评论： 36页，8图

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

我们比较在坍缩背景中的霍金辐射与电场中的施温格对产生。 这种比较是由施温格情况下存在类似视界的事实所驱动的，该视界对经典粒子的时空具有因果分割作用，但量子场可以通过它进行隧穿。 隧穿过程的振幅编码在适当背景耦合波方程解的渐近行为中。 我们使用世界线方法在引力和QED中构造这些解，其中隧穿和粒子产生表现为实时间路径积分的复数鞍点。 对于施温格效应，这些鞍点对应于复数世界线，而对于霍金辐射，相应的世界线是实数的，但在超出某个坐标块后看起来是复数的。 显示英文摘要

We compare Hawking radiation in a collapse background with Schwinger pair creation in an electric field. The comparison is driven by the presence of an analogue horizon in the Schwinger case, which causally divides spacetime for classical particles, but through which quantum fields can tunnel. Amplitudes for tunnelling processes are encoded in the asymptotic behaviour of solutions to the appropriate background-coupled wave equation. We construct these solutions, in both gravity and QED, using the worldline approach, where tunnelling and particle creation manifest as complex saddle points of a real-time path integral. For the Schwinger effect, these saddles correspond to complex worldlines, while for Hawking radiation, the corresponding worldlines are real, but appear complex when extended beyond a certain coordinate patch.

[34] arXiv:2508.01080 (交叉列表自 cond-mat.quant-gas) [中文pdf, pdf, html, 其他]

标题： 非破坏性光机械检测方案用于玻色-爱因斯坦凝聚态 显示英文标题

标题： Nondestructive optomechanical detection scheme for Bose-Einstein condensates

Cisco Gooding, Cameron R. D. Bunney, Samin Tajik, Sebastian Erne, Steffen Biermann, Jörg Schmiedmayer, Jorma Louko, William G. Unruh, Silke Weinfurtner

评论： 14页，2图

主题： 量子气体 (cond-mat.quant-gas) ; 广义相对论与量子宇宙学 (gr-qc)

我们提出一种双频外差光学读出方案，从盘状玻色-爱因斯坦凝聚体中沿任意静态相互作用路径提取不同时刻的密度关联，使用调制激光探测。 分析测量噪声，包括不精确性和反作用，我们确定了信号提取方案的标准量子极限，并研究一类双模压缩初始态如何用于超越这一极限。 作为应用，我们展示该读出方案如何用于实验实现系统中量子真空涨落的加速度依赖性，包括类比时空圆周运动的厄斯金效应。 显示英文摘要

We present a two-tone heterodyne optical readout scheme to extract unequal-time density correlations along an arbitrary stationary interaction path from a pancake-shaped Bose-Einstein condensate, using a modulated laser probe. Analysing the measurement noise both from imprecision and backaction, we identify the standard quantum limit for the signal-extraction scheme, and examine how a class of two-mode squeezed initial states can be used to push beyond this limit. As an application, we show how the readout scheme can be used for an experimental realisation of acceleration-dependence of quantum-vacuum fluctuations in the system, including the analogue spacetime circular motion Unruh effect.

[35] arXiv:2508.01397 (交叉列表自 quant-ph) [中文pdf, pdf, html, 其他]

标题： 通过有限测量时间下压缩输入光增强的重力诱导纠缠 显示英文标题

标题： Enhanced Gravity-Induced Entanglement via Squeezed Input Light under Finite Measurement Time

Kosei Hatakeyama, Daisuke Miki, Yamamoto Kazuhiro

评论： 13页，5图

主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc)

我们研究了在傅里叶域分析中使用压缩输入光生成引力诱导纠缠（GIE）的优势。 基于[1]中的发现，该研究证明了在量子控制下检测GIE在光机械系统中的可行性，我们进一步表明，压缩输入光可以减少机械条件态中的光学噪声并增强GIE。 此外，我们估计了在有限测量时间内通过傅里叶变换测量GIE时的系统误差和统计误差。 基于使用信号噪声比（SNR）进行的误差估计，在GIE检测中，当使用压缩输入光时，需要总测量时间为10^6秒才能达到SNR=1，而无需压缩输入光时则需要10^{6.8}秒。 这一结果突显了光机械系统的有效性以及压缩输入光在增强GIE可检测性中的关键作用。 显示英文摘要

We investigate the advantage of using squeezed input light for generating gravity-induced entanglement (GIE) through Fourier-domain analysis. Based on the findings of [1], which demonstrated the feasibility of detecting GIE in optomechanical systems under quantum control, we further demonstrate that squeezed input light can reduce the optical noise in the mechanical conditional state and enhance GIE. Furthermore, we estimate the systematic and statistical errors in the measurement of GIE using the Fourier transformation over a finite measurement time. Based on the error estimations using the signal-to-noise ratio (SNR) in GIE detection, we find that a total measurement time of 10^6 s is required to achieve SNR=1 when using squeezed input light, whereas 10^{6.8} s is needed without squeezed input light. This result highlights the effectiveness of optomechanical systems and the critical role of squeezed input light in enhancing the detectability of GIE.

[36] arXiv:2508.01446 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 流体/引力中的辐射和平坦极限 显示英文标题

标题： Radiation in Fluid/Gravity and the Flat Limit

Gabriel Arenas-Henriquez, Luca Ciambelli, Felipe Diaz, Weizhen Jia, David Rivera-Betancour

评论： 70页

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

我们探讨了表现出辐射行为的渐近局部反德西特时空，采用允许明确平直极限的空规范。 体内的辐射内容由超泊松向量捕获，我们以双边界理论中的流体变量重新解释这一概念。 对于代数特殊解，我们发现体内的辐射与边界应力张量中的耗散修正之间存在紧密联系，展示了辐射与边界流体中熵产生的直接联系。 这揭示了体内辐射动力学与边界非平衡共形物理之间的丰富相互作用。 随后，我们在平空间全息理论的背景下研究这种对应关系的平直极限。 在此背景下，我们构建了超泊松向量的卡罗尔类似物，并引入了如能量探测器等天体观测量，这些观测量自然地从体内的辐射结构中出现。 我们的分析表明，体内的辐射源激发了卡罗尔粘性应力张量和热流，该张量在此框架中编码了邦迪新闻。 我们通过具体的例子说明了我们的结果，包括 罗宾逊-特劳特曼时空和加速黑洞。 显示英文摘要

We explore asymptotically locally anti-de Sitter spacetimes exhibiting radiative behavior, employing null gauges that allow for a well-defined flat limit. The radiative content in the bulk is captured by the super-Poynting vector, which we reinterpret holographically in terms of fluid variables in the dual boundary theory. For algebraically special solutions, we uncover a close connection between bulk radiation and dissipative corrections in the boundary stress tensor, demonstrating a direct link between radiation and entropy production in the boundary fluid. This reveals a rich interplay between radiative dynamics in the bulk and out-of-equilibrium conformal physics at the boundary. We then investigate the flat limit of this correspondence in the context of flat-space holography. In this setting, we construct a Carrollian analogue of the super-Poynting vector and introduce Celestial observables, such as energy detectors, which emerge naturally from the bulk's radiative structure. Our analysis shows that bulk radiation sources the Carrollian viscous stress tensor and heat current, which encodes the Bondi news in this framework. We illustrate our results with explicit examples, including Robinson-Trautman spacetimes and accelerating black holes.

[37] arXiv:2508.01487 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 宇宙-量子联系：评估Kerr-Newman-Kiselev-Letelier黑洞中弱引力和弱宇宙审查假设的可行性 显示英文标题

标题： Cosmic-Quantum Connections: Assessing the Viability of Weak Gravity and Weak Cosmic Censorship Conjectures in Kerr-Newman-Kiselev-Letelier Black Hole

Saeed Noori Gashti, Behnam Pourhassan

评论： 12页，5图

期刊参考： 物理快报 B（2025）：139730

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

本文针对弱引力猜想（WGC）与弱宇宙审查猜想（WCCC）之间的潜在验证进行研究，这是量子引力中的一个重要挑战。我们探讨了在Kerr-Newman-Kiselev-Letelier（KNKL）黑洞背景下WGC和WCCC的可行性。尽管这些猜想看似无关，但它们之间存在令人惊讶的联系，这在量子与宇宙之间建立了一座桥梁。通过施加对黑洞参数的具体约束，我们证明在某些区域WGC和WCCC可以相容。我们研究了KNKL黑洞在$q/m > (Q/M )_{ext}$时的特性，其中$(Q/M )_{ext}$是大极端黑洞的电荷与质量比。我们提供了图表以同时测试这两个猜想的有效性。 没有自旋参数\(a\)，弦参数\(b\)，暗能量参数\(\gamma\)和状态方程参数\(\omega\)，黑洞如果\(Q^2/M^2 \leq 1\)则有两个事件视界，如果\(Q^2/M^2 > 1\)则没有事件视界，这会导致裸奇点，与WCCC矛盾。 然而，当\(a\),\(b\),\(\gamma\), 和\(\omega\)存在时，黑洞在\(Q^2/M^2 > 1\)的某些区域具有事件视界，确保奇点被覆盖，并且 WGC 和 WCCC 均得到满足。 实际上，我们在黑洞的极端状态中面临这个问题，即这些假说仍然有效，黑洞保持事件视界。 我们得出结论，参数\(a\)、\(b\)、\(\gamma\)和\(\omega\)的某些区域可以使 WGC 和 WCCC 兼容，表明当这些参数存在时它们是一致的。 显示英文摘要

This paper addresses a potential validation of the weak gravity conjecture (WGC) with the weak cosmic censorship conjecture (WCCC), as a significant challenge in quantum gravity. We explore the viability of the WGC and WCCC in the context of the Kerr-Newman-Kiselev-Letelier (KNKL) black hole. Although these conjectures appear unrelated, but surprising connection between these conjectures, It establishes a bridge between the quantum and the cosmic. By imposing specific constraints on the black hole's parameters, we demonstrate that the WGC and WCCC can be compatible in certain regions. We examine the properties of the KNKL black hole for $q/m > (Q/M )_{ext}$, where $(Q/M )_{ext}$ is the charge-to-mass ratio of a large extremal black hole. We present figures to test the validity of both conjectures simultaneously. Without the spin parameter \(a\), the cloud of string parameter \(b\), quintessence parameter \(\gamma\), and equation of state parameter \(\omega\), the black hole either has two event horizons if \(Q^2/M^2 \leq 1\) or none event horizon if \(Q^2/M^2 > 1\) which leads to a naked singularity that contradicts the WCCC. However, when \(a\), \(b\), \(\gamma\), and \(\omega\) are present, the black hole has event horizons in some regions in the \(Q^2/M^2 > 1\) that ensure the singularity is covered and both the WGC and WCCC are fulfilled. Actually, we face this issue in the extremality state of the black hole viz these conjectures remain viable, with the black hole maintaining an event horizon. We conclude that certain regions of \(a\), \(b\), \(\gamma\), and \(\omega\) parameters can make the WGC and WCCC compatible, indicating their agreement when these parameters are present.

[38] arXiv:2508.01614 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 黑洞的扩展热力学拓扑结构 显示英文标题

标题： Extended thermodynamical topology of black hole

Shan-Ping Wu, Si-Jiang Yang, Shao-Wen Wei

评论： 26页，9图

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

热力学拓扑已成为分类黑洞热力学行为的有力框架。 三种不同的但互补的拓扑不变量已被用于表征黑洞相、旋节曲线和黑洞热力学中的临界点。 在本工作中，我们开发了一个统一的框架，整合了这三种拓扑方法，并引入了扩展热力学拓扑的概念，提供了清晰的物理解释。 作为第一步，我们将此框架应用于爱因斯坦引力中的黑洞，系统地阐明了其相结构，以拓扑不变量为依据。 随后，我们将分析扩展到七维洛埃洛克引力中的黑洞，其中从拓扑角度自然出现了新的热力学现象。 此外，我们探讨了临界指数与扩展热力学拓扑之间的联系，揭示了第$k$阶向量场的零点与相关临界指数之间的对应关系。 我们的研究证明，扩展热力学拓扑为分析和分类黑洞相变提供了一个稳健且细致的框架。 显示英文摘要

Thermodynamical topology has emerged as a powerful framework for classifying the thermodynamical behavior of black holes. Three distinct yet complementary topological invariants have been employed to characterize black hole phases, spinodal curves, and critical points in black hole thermodynamics. In this work, we develop a unified framework that integrates these three topological approaches and introduce the concept of extended thermodynamical topology, providing a clear physical interpretation. As a first step, we apply this framework to black holes in Einstein gravity, systematically elucidating their phase structure in terms of topological invariants. We then extend our analysis to black holes in 7-dimensional Lovelock gravity, where novel thermodynamic phenomena naturally emerge from the topological perspective. Moreover, we explore the connection between critical exponents and the extended thermodynamical topology, uncovering a correspondence between the zeros of the $k$-th order vector field and the associated critical exponents. Our study demonstrates that extended thermodynamical topology offers a robust and fine-grained framework for analyzing and classifying black hole phase transitions.

[39] arXiv:2508.01616 (交叉列表自 physics.hist-ph) [中文pdf, pdf, 其他]

标题： 二元论的哲学与物理 显示英文标题

标题： The Philosophy and Physics of Duality

Sebastian De Haro, Jeremy Butterfield

评论： 592页，40幅图，ISBN 9780198846338。这是2024年10月提交出版的书籍文稿。由牛津大学出版社出版，采用开放获取的CC BY-NC-ND许可证，可在此免费下载为PDF：https://global.oup.com/academic/product/the-philosophy-and-physics-of-duality-9780198846338。引用本作品时，请参考已出版版本。

主题： 物理的历史与哲学 (physics.hist-ph) ; 统计力学 (cond-mat.stat-mech) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

本专著讨论了物理学中的对偶性：什么是对偶性，它们的主要例子——从量子力学和电动力学到统计力学、量子场论和弦理论——以及它们引发的哲学问题。 第一部分首先对对偶性进行概念化，并讨论它们的主要作用和主题，包括它们与对称性和解释等熟悉概念之间的关系。 它还讨论了对偶性的主要简单例子：位置-动量、波粒、电-磁和克雷默-瓦尼尔对偶性。 第二部分讨论了高级例子及其相互关系：粒子-孤子对偶性，量子场论中的电-磁对偶性，弦理论中的对偶性，以及规范-引力对偶性。 本部分以洞穴论证的讨论结束，并说明弦理论如何计算黑洞的微观状态。 第三部分深入讨论了与对偶性相关的普遍哲学问题：理论等价（两个理论“用不同的语言说同一件事”）、科学实在论和数据对理论的不确定问题、理论演进和M理论计划、解释和科学理解。 它提出了一种被称为“理论的几何观点”的科学理论观点。 本书对例子的处理处于高级本科和研究生水平，从基础例子开始，逐步进入更高级的例子。 对哲学主题的讨论，如指称语义学、理论等价、科学实在论和科学理解，既自成体系又深入。 因此，本书旨在面向对物理例子和对偶性哲学问题感兴趣的学生和研究人员，同时也关注物理学和哲学如何能够互相有益地互动。 显示英文摘要

This monograph discusses dualities in physics: what dualities are, their main examples--from quantum mechanics and electrodynamics to statistical mechanics, quantum field theory and string theory--and the philosophical questions they raise. Part I first conceptualises dualities and discusses their main roles and themes, including how they are related to familiar notions like symmetry and interpretation. It also discusses the main simple examples of dualities: position-momentum, wave-particle, electric-magnetic, and Kramers-Wannier dualities. Part II discusses advanced examples and their inter-relations: particle-soliton dualities, electric-magnetic dualities in quantum field theories, dualities in string theory, and gauge-gravity duality. This Part ends with discussions of the hole argument, and how string theory counts the microstates of a black hole. Part III is an in-depth discussion of general philosophical issues on which dualities bear: theoretical equivalence (two theories 'saying the same thing, in different words'), scientific realism and the under-determination of theories by data, theory succession and the M-theory programme, explanation, and scientific understanding. It proposes a view of scientific theories that it dubs 'the geometric view of theories'. The book's treatment of the examples is at the advanced undergraduate and graduate level, starting from elementary and progressing to more advanced examples. The discussions of philosophical topics, such as referential semantics, theoretical equivalence, scientific realism and scientific understanding, are both self-contained and in-depth. Thus the book is aimed at students and researchers with an interest in the physical examples and philosophical questions about dualities, and also in how physics and philosophy can fruitfully interact with each other.

[40] arXiv:2508.01652 (交叉列表自 astro-ph.CO) [中文pdf, pdf, 其他]

标题： 宇宙学对$f(T,B)$引力的约束来自早期和晚期宇宙观测 显示英文标题

标题： Cosmological Constraints on $f(T,B)$ Gravity from Observations of Early and Late Universe

Yahia Al-Omar, Majida Nahili, Nidal Chamoun, Marwan Al-Raeei

评论： 18页，6图

主题： 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc)

本研究提出了一种统一框架，包含两种互补方法，通过联合利用早期和晚期宇宙观测数据，对三种功能形式的$f(T,B)$引力进行约束，即线性、二次和一般幂律模型。 首先，我们根据原初氦-4质量分数的最新测量结果，对弱相互作用冻结温度的偏差施加限制。 其次，我们引入直接的哈勃参数数据，$H(\mathcal{z})$，这些数据来自红移范围$0.07\le\mathcal{z}\le2.0$内的宇宙计时器，以追踪宇宙的膨胀历史。 通过在两个数据集上最小化组合卡方统计量，我们得到了每个模型参数的最佳拟合值和置信区间。 联合分析相比仅基于大爆炸核合成的方法显著改进了参数约束，从而为$f(T,B)$引力在宇宙时期的测试提供了更稳健的检验。 结果支持基于扭力的广义相对论修正的可行性，并为未来使用即将到来的观测数据进行评估提供了一致的方法。 显示英文摘要

This study proposes a unified framework comprising two complementary approaches to constrain three functional forms of $f(T,B)$ gravity, namely the linear, quadratic, and general power law models, by jointly utilizing early and late Universe observations. First, we impose bounds on deviations in the weak interaction freeze-out temperature, informed by the latest measurements of the primordial helium-4 mass fraction. Second, we incorporate direct Hubble parameter data, $H(\mathcal{z})$, obtained from Cosmic Chronometers in the redshift range $0.07\le\mathcal{z}\le2.0$, to trace the expansion history of the Universe. By minimizing a combined chi-square statistic across both datasets, we derive the best-fit values and confidence intervals for each model parameter. The joint analysis significantly refines the parameter constraints compared to methods based solely on Big Bang Nucleosynthesis, thereby offering a more robust test of $f(T,B)$ gravity across cosmic epochs. The results support the viability of torsion-based modifications to General Relativity and provide a consistent methodology for future evaluation using upcoming observational data.

[41] arXiv:2508.01654 (交叉列表自 cond-mat.quant-gas) [中文pdf, pdf, html, 其他]

标题： 集体激发的参数对产生在玻色-爱因斯坦凝聚体中 显示英文标题

标题： Parametric pair production of collective excitations in a Bose-Einstein condensate

Victor Gondret, Rui Dias, Clothilde Lamirault, Léa Camier, Amaury Micheli, Charlie Leprince, Quentin Marolleau, Scott Robertson, Denis Boiron, Christoph I. Westbrook

评论： 5+5页，本文献献给雷诺·帕伦坦

主题： 量子气体 (cond-mat.quant-gas) ; 广义相对论与量子宇宙学 (gr-qc) ; 模式形成与孤子 (nlin.PS) ; 量子物理 (quant-ph)

通过激发伸长的玻色-爱因斯坦凝聚体的横向呼吸模式，我们以成对的方式参数地产生纵向集体激发。 这一过程也被称为法拉第波生成，可以看作是宇宙学粒子生成的类比。 在单粒子检测的基础上，我们研究了指数增长的早期时间动力学，并将我们的观察结果与布洛赫诺夫描述进行比较。 我们实验观察到的增长率与理论预测非常吻合，证明了布洛赫诺夫描述的有效性，从而确认了这种伸长气体中准粒子相互作用的微小性。 我们还讨论了原子数中的振荡现象，这些振荡是由于成对关联以及相互作用被关闭的速度引起的。 显示英文摘要

By exciting the transverse breathing mode of an elongated Bose-Einstein condensate, we parametrically produce longitudinal collective excitations in a pairwise manner. This process also referred to as Faraday wave generation, can be seen as an analog to cosmological particle production. Building upon single particle detection, we investigate the early time dynamics of the exponential growth and compare our observation with a Bogoliubov description. The growth rate we observe experimentally is in very good agreement with theoretical predictions, demonstrating the validity of the Bogoliubov description and thereby confirming the smallness of quasiparticle interactions in such an elongated gas. We also discuss the presence of oscillations in the atom number, which are due to pair correlations and to the rate at which interactions are switched off.

[42] arXiv:2508.01804 (交叉列表自 math-ph) [中文pdf, pdf, html, 其他]

标题： 关联勒让德圆锥函数的性质 显示英文标题

标题： Properties of associated Legendre conical functions

Daniel A. Norman, Philip D. Mannheim, Tianye Liu

评论： 22页

主题： 数学物理 (math-ph) ; 广义相对论与量子宇宙学 (gr-qc)

我们介绍了一些关于第一类和第二类关联勒让德圆锥函数的新的性质，$P^{-1/2-K}_{-1/2+i \tau}(\chi)$和$Q^{-1/2-K}_{-1/2+i \tau}(\chi)$。 特别地，我们证明了对于任何一般的$K$，当$K$是非负整数$\ell$时，$n$可以从$-\ell$到$\ell$按单位步长变化，否则可以从$-\infty$到$\infty$按单位步长变化，其中$\tau$是独立的$\mathcal{R}^{K}_{n}(\chi)=(2\pi)^{-3/2}\tanh^{-K}\chi\sinh^{-1/2}\chi[\Gamma(1+K)]^{-1}\int_{0}^{2\pi} d\omega \left (1-\cos \omega/\cosh\chi\right)^{K}e^{in\omega}$，我们可以设置$P^{-1/2-K}_{-1/2+i \tau}(\chi)=2\sum_{n}\mathcal{R}^{K}_{n}(\chi)\sin[(\tau-in)\chi)]/(\tau-in)$。 我们也可以设置$Q^{-1/2-K}_{-1/2+i \tau}(\chi)=-\pi\sum_n\mathcal{R}^K_{n-K}(\chi)e^{-i \chi(\tau-i(n-K))}/(\tau-i(n-K))$，其中$n$从$0$到$2\ell$按单位步长变化，当$K$是非负整数$\ell$时，否则从$0$到$\infty$按单位步长变化。 通过这些形式隔离整个 $\tau$ 的依赖关系，特别是其相关的极点结构，我们可以使用这些形式来确定关于 $\tau$ 的相关连带勒让德锥函数及其乘积的积分的闭合形式表达式。 $Q^{-1/2-K}_{-1/2+i \tau}(\chi)$ 具有一个包含积分 $\int_{\chi}^{\infty}d\omega e^{i\omega\tau}(\cosh\omega-\cosh\chi)^{K}$ 的积分表示，该积分仅在 $\omega=\infty$ 时收敛，如果 ${\rm Re}[K]<{\rm Im}[\tau]$。 我们说明如何利用此积分在此范围之外的散度，以表征复数$\tau$平面极点结构的$Q^{-1/2-K}_{-1/2+i \tau}(\chi)$。 我们提出了一种对 Borwein 积分和 Nyquist-Shannon 采样定理的新处理方法。 显示英文摘要

We present some new properties of associated Legendre conical functions of the first and second kind, $P^{-1/2-K}_{-1/2+i \tau}(\chi)$ and $Q^{-1/2-K}_{-1/2+i \tau}(\chi)$. In particular we show that with the $\tau$-independent $\mathcal{R}^{K}_{n}(\chi)=(2\pi)^{-3/2}\tanh^{-K}\chi\sinh^{-1/2}\chi[\Gamma(1+K)]^{-1}\int_{0}^{2\pi} d\omega \left (1-\cos \omega/\cosh\chi\right)^{K}e^{in\omega}$ for any general $K$, we can set $P^{-1/2-K}_{-1/2+i \tau}(\chi)=2\sum_{n}\mathcal{R}^{K}_{n}(\chi)\sin[(\tau-in)\chi)]/(\tau-in)$, where $n$ ranges from $-\ell$ to $\ell$ in unit steps when $K$ is a non-negative integer $\ell$, and from $-\infty$ to $\infty$ in unit steps otherwise. Also we can set $Q^{-1/2-K}_{-1/2+i \tau}(\chi)=-\pi\sum_n\mathcal{R}^K_{n-K}(\chi)e^{-i \chi(\tau-i(n-K))}/(\tau-i(n-K))$, where $n$ ranges from $0$ to $2\ell$ in unit steps when $K$ is a non-negative integer $\ell$, and from $0$ to $\infty$ in unit steps otherwise. With these forms isolating the entire $\tau$ dependence, and especially its associated pole structure, we can use these forms to determine closed form expressions for integrals over $\tau$ of associated Legendre conical functions and their products. The $Q^{-1/2-K}_{-1/2+i \tau}(\chi)$ have an integral representation containing the integral $\int_{\chi}^{\infty}d\omega e^{i\omega\tau}(\cosh\omega-\cosh\chi)^{K}$, an integral that only converges at $\omega=\infty$ if ${\rm Re}[K]<{\rm Im}[\tau]$. We show how to use the divergence of this integral outside of this range in order to characterize the complex $\tau$ plane pole structure of $Q^{-1/2-K}_{-1/2+i \tau}(\chi)$. We present a new treatment of the Borwein integral and the Nyquist-Shannon sampling theorem.

[43] arXiv:2508.01855 (交叉列表自 astro-ph.CO) [中文pdf, pdf, html, 其他]

标题： $\texttt{GENGARS}$: N体模拟中具有任意三阶谱的精确非高斯初始条件 显示英文标题

标题： $\texttt{GENGARS}$: Accurate non-Gaussian initial conditions with arbitrary bispectrum for N-body simulations

Emanuele Fondi, Licia Verde, Marco Baldi, William Coulton, Francisco Villaescusa-Navarro, Benjamin Dan Wandelt

评论： 19页，7张图。欢迎提出意见！

主题： 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc)

原初非高斯性被各种暴胀模型所预测，而N体模拟是研究其在大尺度结构上印记的关键工具。 在本工作中，我们介绍了\texttt{GENGARS}（GEnerator of Non-Gaussian ARbitrary Shapes），一个用于生成N体模拟的精确非高斯初始条件的框架。 它基于Wagner & Verde（2012）提出的公式，能够生成具有所需可分离三阶谱的原初引力势$B_{\Phi}(k_1,k_2,k_3)$。 对于局部、等边和正交的非高斯模板，我们将我们的方法与已建立的\texttt{2LPT-PNG}代码进行对比。 我们表明，\texttt{GENGARS}通过抑制原初功率谱中的虚假贡献，实现了更高的精度和更低的噪声。 本文旨在介绍该方法，量化其性能，并说明其相对于现有方法的优势和适用案例。 显示英文摘要

Primordial non-Gaussianity is predicted by various inflationary models, and N-body simulations are a crucial tool for studying its imprints on large-scale structure. In this work, we present \texttt{GENGARS} ( GEnerator of Non-Gaussian ARbitrary Shapes), a framework for generating accurate non-Gaussian initial conditions for N-body simulations. It builds upon the formulation introduced by Wagner \& Verde (2012), enabling to generate a primordial gravitational potential with a desired separable bispectrum $B_{\Phi}(k_1,k_2,k_3)$. For the local, equilateral and orthogonal non-Gaussian templates, we benchmark our method against the well-established \texttt{2LPT-PNG} code. We show that \texttt{GENGARS} achieves improved accuracy and lower noise by suppressing spurious contributions to the primordial power spectrum. This paper aims at presenting the method, quantifying its performance and illustrating the benefits and applicable use cases over existing approaches.

[44] arXiv:2508.01901 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 世界线瞬子对于由时空依赖引力场非微扰粒子产生的影响 显示英文标题

标题： Worldline instantons for nonperturbative particle production by space and time dependent gravitational fields

Philip Semrén, Greger Torgrimsson

评论： 21页，20图

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

我们开发了一种世界线瞬子方法，用于计算由同时依赖于空间和时间的引力场产生的粒子动量谱。 瞬子是开放的。 中间部分是复数，描述了形成区域，而两端描述了渐近粒子的轨迹。 显示英文摘要

We develop a worldline-instanton approach for calculating the momentum spectrum of particles produced by gravitational fields which depend on both space and time. The instantons are open. The middle part is complex and describes the formation region, while the ends describe the trajectories of asymptotic particles.

[45] arXiv:2508.01998 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]

标题： 重新审视多项式混合暴胀：通过辐射修正实现普朗克和ACT的兼容性 显示英文标题

标题： Revisiting Polynomial Hybrid Inflation: Planck and ACT Compatibility via Radiative Corrections

Waqas Ahmed, Saleh O. Allehabi, Mansoor Ur Rehman

评论： 15页，3图

主题： 高能物理 - 现象学 (hep-ph) ; 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

我们研究在非超对称的混合暴胀模型中，单环辐射修正对混沌（多项式类似）势$V(\phi) = V_0 + \lambda_p \phi^p$的影响，在最新来自\textit{普朗克}和\textit{阿塔卡马宇宙学望远镜}（ACT）观测约束的背景下。 在这里，$V_0$表示暴胀的能量尺度，而$\lambda_p$是与幂次为$p$的多项式项相关的耦合。 这些修正可以自然地来自于标量场与其他物质场的耦合，这也有助于再加热过程。 在树级别，此类模型对标量谱指数$n_s$和张量-标量比$r$的预测通常超出当前观测界限。 然而，引入一环辐射修正会修改势能为\[ V(\phi) = V_0 + \lambda_p \phi^p + A \phi^4 \ln (\phi/ \mu), \]，其中$A$表征暴胀场与其他场耦合的强度，而\(\mu\)是适当的重整化尺度。 这种辐射修正后的势能可以在本文探讨的参数空间的适当范围内使模型与\textit{普朗克}+ACT 数据相一致。 特别是，费米子环路的辐射修正（$A < 0$）抑制了张量-标量比$r$，同时产生了一个红倾斜的谱 with$n_s < 1$，即使在普朗克场激发之下。这使预测与当前观测一致，同时仍允许原初引力波的潜在可探测特征。此外，暴胀子的耦合实现了成功的再加热，并自然地容纳了非热重子生成，为暴胀和重子生成提供了一个统一的框架。 显示英文摘要

We investigate the impact of one-loop radiative corrections in a non-supersymmetric model of hybrid inflation with a chaotic (polynomial-like) potential,$V(\phi) = V_0 + \lambda_p \phi^p$, in the light of the latest constraints from \textit{Planck} and \textit{Atacama Cosmology Telescope} (ACT) observations. Here, $V_0$ denotes the energy scale of inflation, and $\lambda_p$ is a coupling associated with the polynomial term of power $p$. These corrections can naturally arise from couplings of the inflaton to other matter fields, which also facilitate the reheating process. At the tree level, the predictions of such models for the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ typically lie outside the current observational bounds. However, incorporating one-loop radiative corrections modifies the potential to, \[ V(\phi) = V_0 + \lambda_p \phi^p + A \phi^4 \ln (\phi/ \mu), \] where $A$ characterizes the strength of the inflaton's coupling to other fields, and \(\mu\) is an appropriate renormalization scale. This radiatively corrected potential can reconcile the model with the combined \textit{Planck}+ACT data over a suitable range of parameter space explored in this work. In particular, radiative corrections from fermionic loops ($A < 0$) suppress the tensor-to-scalar ratio $r$, while simultaneously yielding a red-tilted spectrum with $n_s < 1$, even for sub-Planckian field excursions. This brings the prediction in line with current observations, while still allowing for potentially detectable signatures of primordial gravitational waves. Furthermore, the inflaton's couplings enable successful reheating and naturally accommodate non-thermal leptogenesis, providing a unified framework for inflation and baryogenesis.

[46] arXiv:2508.02174 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： AdS4中带电毛发黑洞的平稳解：Kasner内部结构、旋转冲击波与快速混乱 显示英文标题

标题： Stationary Solution to Charged Hairy Black Hole in AdS4: Kasner Interior, Rotating Shock Waves, and Fast Scrambling

Hadyan Luthfan Prihadi, Rafi Rizqy Firdaus, Fitria Khairunnisa, Donny Dwiputra, Freddy Permana Zen

评论： 39页

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

我们考虑在AdS$_4$中带有标量电荷的静态黑洞解，其中标量场与$U(1)$麦克斯韦规范场耦合。在奇点附近，时空过渡到更一般的卡斯纳几何结构。然后在Dray-'t Hooft解中向黑洞注入旋转和带电的引力冲击波。这些冲击波拉长连接两个渐近边界的虫洞，从而破坏它们之间的关联。关联由左侧和右侧边界上子区域之间的量子互信息量化，在一个称为编织时间的特征时间尺度上消失，该时间尺度对黑洞熵呈对数依赖。互信息通过纠缠熵的Ryu-Takayanagi方案进行全息计算。我们研究黑洞和冲击波的旋转和电荷如何影响诸如编织时间和李雅普诺夫指数等混沌特性。黑洞和冲击波电荷之间的相互作用引入了编织过程的延迟。我们发现，随着边界变形强度的增加，李雅普诺夫指数和编织时间延迟均单调减少。此外，冲击波的角动量增强了李雅普诺夫指数和编织时间延迟。 显示英文摘要

We consider a stationary solution of a charged black hole with scalar hair in AdS$_4$, where the scalar field is coupled to a $U(1)$ Maxwell gauge field. Near the singularity, the spacetime transitions into a more general Kasner geometry. The black hole is then injected with rotating and charged gravitational shock waves in the Dray-'t Hooft solution. These shock waves lengthen the wormhole connecting the two asymptotic boundaries, thereby disrupting the correlations between them. The correlation, quantified by the quantum mutual information between subregions on the left and right boundaries, vanishes at a characteristic timescale known as the scrambling time, which depends logarithmically on the black hole entropy. The mutual information is computed holographically using the Ryu-Takayanagi prescription for entanglement entropy. We investigate how the rotation and charge of both the black hole and the shock waves affect chaotic properties such as the scrambling time and the Lyapunov exponent. The interaction between the charges of the black hole and the shock waves introduces a delay in the scrambling process. We find that as the strength of the boundary deformation increases, both the Lyapunov exponent and the scrambling time delay decrease monotonically. Furthermore, the angular momentum of the shock waves enhances both the Lyapunov exponent and the scrambling time delay.

[47] arXiv:2508.02205 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 四维编织非对易引力的物理意义 显示英文标题

标题： Physical implications of four dimensional braided noncommutative gravity

Milorad Bežanić, Marija Dimitrijević Ćirić, Biljana Nikolić, Voja Radovanović

评论： 18页

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

在非对易（NC）时空上构建引力理论一直是研究的活跃领域。 文献中提出了各种模型和方法。 即使在乘积形式的框架下，也有几种不同的方法来构建广义相对论（GR）和爱因斯坦-卡坦-帕拉蒂尼（ECP）引力的非对易变形。 一些模型基于非对易局部洛伦兹对称性，而其他模型则依赖于GR微分同胚对称性的非对易变形。 在本文中，我们研究了基于扭曲和编织非对易微分同胚对称性的两种非对易引力模型之间的联系。 尽管这两个模型产生不同的非对易引力作用量，但我们表明，在某些情况下，它们会导致相同的现象学后果。 特别是，它们具有相同的三引力子顶点，并表现出一些简单的共同真空解。 这项工作是理解在乘积框架内构建的非对易引力模型多样化景观的一个步骤。 显示英文摘要

The formulation of gravity theories on noncommutative (NC) spacetimes has been an active area of research for some time. Various models and methods have been proposed in the literature. Even within the star-product formalism, there are several distinct approaches to constructing NC deformations of General Relativity (GR) and Einstein-Cartan-Palatini (ECP) gravity. Some models are based on the NC local Lorentz symmetry, while others rely on NC deformations of the diffeomorphism symmetry of GR. In this paper, we investigate the connection between two NC gravity models based on twisted and braided NC diffeomorphism symmetry. Although these two models yield different NC gravity actions, we show that, in certain cases, they lead to the same phenomenological consequences. In particular, they share identical three-graviton vertex and exhibit some simple common vacuum solutions. This work represents a step towards understanding the diverse landscape of NC gravity models constructed within the star-product framework.

[48] arXiv:2508.02457 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 求和关于3-流形的同调群 显示英文标题

标题： Summing over homology groups of 3-manifolds

Thomas Nicosanti, Pavel Putrov

评论： 55页，3图

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc) ; 数学物理 (math-ph) ; 几何拓扑 (math.GT) ; 数论 (math.NT)

我们考虑一个三维拓扑量子引力的玩具模型。 在这个模型中，给定三维流形的贡献由一个阿贝尔拓扑量子场论（TQFT）的划分函数给出，在边界处有拓扑边界条件。 利用TQFT划分函数仅依赖于三维流形的一阶同调群以及一些额外结构的事实，固定边界的全部三维流形的求和可以重写为有限生成阿贝尔群（以及额外结构）的求和。 我们给出了求和中通用权重的界限，即在有限生成阿贝尔群（带有额外结构）的同构类集合上的测度，足以使求和收敛。 此外，在对测度的进一步假设下，我们论证了二维TQFT分布的存在性，使得求和等于它们在边界上划分函数的系综平均值。 对于某种类型的测度，阿贝尔群的求和可以分解为阿贝尔$p$-群的求和，并且可以独立地对每个素数$p$进行分析。 显示英文摘要

We consider a toy model of a 3-dimensional topological quantum gravity. In this model, a contribution of a given 3-manifold is given by the partition function of an abelian Topological Quantum Field Theory (TQFT), with a topological boundary condition at the boundary. Using the fact that the TQFT partition function depends only on the first homology group of the 3-manifold with some additional structure, the sum over all 3-manifolds with fixed boundary can be rewritten as a sum over finitely generated abelian groups (and the extra structure). We present bounds on the universal weights in the sum, that is, the measure on the set of isomorphism classes of finitely generated abelian groups (with the extra structure) sufficient for the sum to be convergent. Moreover, with further assumptions on the measure, we argue the existence of a distribution of 2d TQFTs, such that the sum is equal to the ensemble average of their partition functions evaluated on the boundary. For a certain kind of measure, the sum over the abelian groups can be factorized into sums over abelian $p$-groups, and the analysis can be performed independently for each prime $p$.

[49] arXiv:2508.02628 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]

标题： 量子变分学在格点上 显示英文标题

标题： Quantum variational calculus on a lattice

Shahn Majid, Francisco Simão

评论： 32页LaTeX，无图表

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc) ; 量子代数 (math.QA)

我们解决了在非交换空间或时空上变分法的长期问题，针对具有平凡喷射丛的一类重要模型。 我们的方法包括Anderson变分双重复形$\Omega(J^\infty)$的量子版本，并包含欧拉-拉格朗日方程和部分诺特定理。 我们详细展示了如何在作为离散非交换几何的$\Bbb Z^m$晶格上的自由场中应用此方法，得到标量场的克莱因-戈登方程，包括在一般度规和规范场背景下的情况，作为作用量的运动欧拉-拉格朗日方程。 在平坦度规的情况下，我们也得到了晶格上标量场的严格在壳守恒的能量-动量张量和诺特电荷。 显示英文摘要

We solve the long-standing problem of variational calculus on a noncommutative space or spacetime for a significant class of models with trivial jet bundle. Our approach entails a quantum version of the Anderson variational double complex $\Omega(J^\infty)$ and includes Euler-Lagrange equations and a partial Noether's theorem. We show in detail how this works for a free field on a $\Bbb Z^m$ lattice regarded as a discrete noncommutative geometry, obtaining the Klein-Gordon equation for a scalar field, including with a general metric and gauge field background, as the Euler-Lagrange equations of motion for an action. In the case of a flat metric we also obtain an exactly on-shell conserved stress-energy tensor and Noether charges for a scalar field on the lattice.

替换提交 (展示 25 之 25 条目 )

[50] arXiv:2401.15789 (替换) [中文pdf, pdf, html, 其他]

标题： 空隙中的反重力：分形时空中的梅根海绵案例 显示英文标题

标题： Anti-Gravity from Vacancies in Fractal Space-Time: The Case of a Menger Sponge

Karl Svozil

评论： 10页，3图，大幅修订

主题： 广义相对论与量子宇宙学 (gr-qc)

我们提出，反重力，作为物质与物质的排斥，可能在由空缺（变薄）而不是增加物质所表征的时空分形框架中自然出现。 使用门格海绵作为原型，我们为嵌入观察者构建一个有效的负质量类似施瓦茨希尔德的度规，并计算由此产生的曲率。 我们将该度规进行解释，以推导局部排斥的条件。 我们还讨论相关的能量条件违反、稳定性问题以及可检验的预测。 显示英文摘要

We propose that anti-gravity, interpreted as matter-matter repulsion, may emerge naturally in a fractal framework of spacetime characterized by vacancies (thinning out) rather than added matter. Using the Menger Sponge as a prototype, we construct an effective negative-mass Schwarzschild-like metric for embedded observers and compute the resulting curvature. We interpret the metric to derive the conditions for local repulsion. We also discuss the associated energy-condition violations, stability issues, and testable predictions.

[51] arXiv:2405.08303 (替换) [中文pdf, pdf, 其他]

标题： 四维空间中的二阶双标量-张量场方程 显示英文标题

标题： Second-Order Bi-Scalar-Tensor Field Equations in a Space of Four-Dimensions

Gregory W. Horndeski

评论： 72页，没有图表。本文替换了先前的一个版本，其中主要定理及其大部分证明是错误的。

主题： 广义相对论与量子宇宙学 (gr-qc)

以两个标量场、伪黎曼度规张量及其任意阶微分的导数为共变的拉格朗日标量密度在四维空间中被研究。 我构建了从这种拉格朗日量可推导出的最一般的二阶欧拉-拉格朗日张量密度。 证明了所有这样的二阶欧拉-拉格朗日张量密度都可以从一组十一拉格朗日量中推导出来，这些拉格朗日量最多是二阶的。 在这十一拉格朗日量中，有六个不涉及度规张量的二阶导数，并且在标量场的二阶导数中代数上最多是一次的。 这十一拉格朗日量中的每一个都将有一个标量系数，该系数是五个变量的共变量：两个标量场，以及两个标量场梯度的三个内积。 在这十一系数函数中，只有一个可以是任意的，而其他十个必须满足线性偏微分方程。 令人惊讶的是，这些偏微分方程与2+1维闵可夫斯基空间中的波动方程有关。 本文最后对一个能产生任意维度空间中最为一般的二阶多标量-张量场方程的拉格朗日量可能具有的形式进行了几点观察。 显示英文摘要

Lagrange scalar densities which are concomitants of two scalar fields, a pseudo-Riemannian metric tensor, and their derivatives of arbitrary differential order are investigated in a space of four-dimensions. I construct the most general second-order Euler-Lagrange tensor densities derivable from such a Lagrangian. It is demonstrated that all such second-order Euler-Lagrange tensor densities can be derived from a set of eleven Lagrangians which are at most of second-order. Of these eleven Lagrangians six do not involve the second derivatives of the metric tensor, and are algebraically at most of first degree in the second derivatives of the scalar fields. Each of the eleven Lagrangians will have a scalar coefficient which is a concomitant of five variables: the two scalar fields, and the three inner products of the gradients of the two scalar fields. Of these eleven coefficient functions only one is arbitrary, while the other ten must satisfy linear partial differential equations. Surprisingly these partial differential equations are related to the wave equation in 2+1 dimensional Minkowski space. The paper concludes with a few observations on the form that a Lagrangian which yields the most general second-order, multi-scalar-tensor field equations in a space of arbitrary dimension can assume.

[52] arXiv:2412.20789 (替换) [中文pdf, pdf, html, 其他]

标题： 预训练音频Transformer作为引力波的基础人工智能工具 显示英文标题

标题： Pre-trained Audio Transformer as a Foundational AI Tool for Gravitational Waves

Chayan Chatterjee, Abigail Petulante, Karan Jani, Jesse Spencer-Smith, Yang Hu, Roy Lau, Haowei Fu, Trang Hoang, Stephen Chong Zhao, Suyash Deshmukh

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能天体物理现象 (astro-ph.HE)

随着引力波探测器变得越来越先进和敏感，由高级LIGO和Virgo记录的来自合并致密天体的信号数量预计将会大幅增加。 这种检测率的激增需要开发适应性强、可扩展且高效的工具，以应对引力波天文学中的各种任务。 基础人工智能模型在此背景下提供了一个变革性的机会，通过提供一个统一的框架，可以在利用大规模预训练能力的同时，针对多种应用进行微调。 在本工作中，我们探讨了先进的变换器模型，特别是OpenAI的Whisper，如何被适配为引力波数据分析的基础模型。 通过微调原本在大量音频数据上训练的Whisper编码器模型，并结合用于专门任务的神经网络，我们在检测天体物理信号和分类瞬态噪声伪影或故障方面取得了可靠的结果。 这是首次将开源变换器模型应用于与之无关任务的预训练，用于引力波研究，展示了它们在检测率迅速增加的时代，实现灵活高效数据分析的潜力。 显示英文摘要

As gravitational wave detectors become more advanced and sensitive, the number of signals recorded by Advanced LIGO and Virgo from merging compact objects is expected to rise dramatically. This surge in detection rates necessitates the development of adaptable, scalable, and efficient tools capable of addressing a wide range of tasks in gravitational wave astronomy. Foundational AI models present a transformative opportunity in this context by providing a unified framework that can be fine tuned for diverse applications while leveraging the power of large scale pre training. In this work, we explore how advanced transformer models, specifically Whisper by OpenAI, can be adapted as a foundational model for gravitational wave data analysis. By fine tuning the encoder model of Whisper, originally trained on extensive audio data, and combining it with neural networks for specialized tasks, we achieve reliable results in detecting astrophysical signals and classifying transient noise artifacts or glitches. This represents the first application of open source transformer models, pre trained on unrelated tasks, for gravitational wave research, demonstrating their potential to enable versatile and efficient data analysis in the era of rapidly increasing detection rates.

[53] arXiv:2501.15676 (替换) [中文pdf, pdf, html, 其他]

标题： 球对称黑洞吸积的多组分流体相对论状态方程中的引力作为涌现现象 显示英文标题

标题： Gravity as emergent phenomena for spherically symmetric black hole accretion of multi-component flow with relativistic equation of state

Tuhin Paul, Aishee Chakraborty, Souvik Ghose, Tapas K. Das

评论： 13页，6张图，RevTeX双栏格式，新版本更正了拼写错误并提高了清晰度，已接受发表于《物理评论D》

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能天体物理现象 (astro-ph.HE)

我们研究了由于非旋转黑洞的球对称吸积流的线性扰动而产生的类比引力现象，其中引力场由一组后牛顿伪施瓦茨希尔德黑洞势确定，而下落物质由相对论多组分状态方程描述。 构建了对应于上述类型吸积系统稳态的定态超音速积分吸积解，并通过吸积流的时间依赖线性扰动对这些解进行了稳定性分析。 这种线性稳定性分析导致在下落物质内部形成了类似黑洞的声学度规。 然后通过构建因果结构，即卡特-彭罗斯图来识别声学视界。 已经研究了与上述声学度规对应的类比表面重力随控制吸积流的各种参数的变化情况。 显示英文摘要

We investigate analogue gravity phenomena arising as a result of the linear perturbation of the spherically symmetric accretion flows onto non rotating black holes, where the gravitational field is determined by a set of post Newtonian pseudo Schwarzschild black hole potentials and the infaling matter is described by a relativistic multi-species equation of state. The stationary transonic integral accretion solutions corresponding to the steady state of aforementioned type of accreting systems are constructed and the stability analysis of such solutions are performed through the time dependent linear perturbation of the accretion flow. Such linear stability analysis leads to the formation of a black hole like sonic metric embedded within the infalling matter. The acoustic horizons are then identified by constructing the causal structure, i.e., the Carter-Penrose diagrams. The variation of the analogue surface gravity corresponding to the aforementioned sonic metric has been studied as a function of various parameters governing the accretion flow.

[54] arXiv:2504.20543 (替换) [中文pdf, pdf, html, 其他]

标题： 使用轨道平均演化方程研究偏心轨道上进动双黑洞的演化 显示英文标题

标题： Evolution of precessing binary black holes on eccentric orbits using orbit-averaged evolution equations

Khun Sang Phukon, Nathan K. Johnson-McDaniel, Amitesh Singh, Anuradha Gupta

评论： 已接受的《物理评论D》版本

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能天体物理现象 (astro-ph.HE)

最一般的双黑洞（BBH）系统具有偏心轨道和进动的自旋。 在合并附近检测到具有显著偏心率的此类系统将是动态形成的明确标志。 为了研究此类系统，重要的是能够从二进制形成时的较大分离度演化其自旋和偏心率到较小的分离度，或者反之亦然。 对二进制轨道角动量进动演化的了解也可用于扭曲对齐自旋的偏心波形模型，以创建一个自旋进动的偏心波形模型。 在本文中，我们介绍了一个新的公开可用代码，使用文献中的轨道平均后牛顿（PN）方程来演化偏心、进动的BBH。 自旋进动动力学是2PN精度的，即包括主要的自旋-轨道和自旋-自旋修正。 轨道参数（轨道频率、偏心率和近日点进动）遵循准开普勒参数化，其精度为3PN，在点粒子项中包括主要的自旋-轨道和自旋-自旋效应。 所有自旋-自旋项都包括四极-单极相互作用。 通量中的偏心率增强函数使用了Loutrel和Yunes [Classical Quantum Gravity{\bf 34}044003 (2017)] 中的高精度超渐近展开。 我们讨论了该代码的各种特性，并研究了偏心、进动的BBH的轨道和自旋进动参数的演化。 特别是，我们研究了自旋形态对偏心率的依赖性，发现从一种自旋形态到另一种自旋形态的转变点可能非单调地依赖于偏心率，而在种群演化过程中某一时刻处于特定形态的二进制分数取决于瞬时偏心率。 显示英文摘要

The most general bound binary black hole (BBH) system has an eccentric orbit and precessing spins. The detection of such a system with significant eccentricity close to the merger would be a clear signature of dynamical formation. In order to study such systems, it is important to be able to evolve their spins and eccentricity from the larger separations at which the binary formed to the smaller separations at which it is detected, or vice versa. Knowledge of the precessional evolution of the binary's orbital angular momentum can also be used to twist up aligned-spin eccentric waveform models to create a spin-precessing eccentric waveform model. In this paper, we present a new publicly available code to evolve eccentric, precessing BBHs using orbit-averaged post-Newtonian (PN) equations from the literature. The spin-precession dynamics is 2PN accurate, i.e., with the leading spin-orbit and spin-spin corrections. The evolution of orbital parameters (orbital frequency, eccentricity, and periastron precession), which follow the quasi-Keplerian parametrization, is 3PN accurate in the point particle terms and includes the leading order spin-orbit and spin-spin effects. All the spin-spin terms include the quadrupole-monopole interaction. The eccentricity enhancement functions in the fluxes use the high-accuracy hyperasymptotic expansions from Loutrel and Yunes [Classical Quantum Gravity {\bf 34} 044003 (2017)]. We discuss various features of the code and study the evolution of the orbital and spin-precession parameters of eccentric, precessing BBHs. In particular, we study the dependence of the spin morphologies on eccentricity, where we find that the transition point from one spin morphology to another can depend nonmonotonically on eccentricity, and the fraction of binaries in a given morphology at a given point in the evolution of a population depends on the instantaneous eccentricity.

[55] arXiv:2504.20701 (替换) [中文pdf, pdf, html, 其他]

标题： 宇宙学中的静态视界 显示英文标题

标题： Static horizons in cosmology

Ida M. Rasulian, Amjad Ashoorioon

评论： 19页，4图，已更新并改进

主题： 广义相对论与量子宇宙学 (gr-qc) ; 宇宙学与非星系天体物理学 (astro-ph.CO) ; 高能物理 - 现象学 (hep-ph) ; 高能物理 - 理论 (hep-th)

尽管以前的结果排除了宇宙学中存在静态视界的可能性，但我们提出了保留静态视界的黑洞和白洞度规，同时在大距离处再现宇宙学行为。 通过选择适当的坐标，我们证明在宇宙学环境中可以存在静态视界，而不会在视界处引入曲率不变量奇点。 该结果度规在哈勃参数为常数时退化为史瓦西-德西特解。 我们发现，在膨胀宇宙中的白洞度规（或在收缩宇宙中的黑洞度规）更容易构建，因为膨胀宇宙中的黑洞需要速度函数改变符号。 因此，这项工作主要研究膨胀宇宙中的白洞，作为后续分析膨胀宇宙中黑洞的基础。 在后面的章节中，我们研究了白洞与宇宙学物质耦合的情况，以及白洞同时包含物质和宇宙学常数的情况。 假设压力分量取其宇宙学值，我们表明可观测视界的物理半径在晚期时间可以渐近趋近于一个常数值。 该度规避免了哈勃参数趋近于零极限下的病态，例如视界奇点。 最后，我们分析了嵌入无压宇宙学物质中的真实黑洞情况，包括有和没有宇宙学常数的情况，并探讨了其特性。 显示英文摘要

Although previous results have ruled out the possibility of a static horizon in cosmology, we present black hole and white hole metrics that retain static horizons while reproducing cosmological behavior at large distances. Using an appropriate coordinate choice, we demonstrate that a static horizon can exist in a cosmological setting without introducing curvature invariant singularities at the horizon. The resulting metric reduces to the Schwarzschild de Sitter solution when the Hubble parameter is constant. We find that white hole metrics in an expanding universe (or black holes in a contracting universe) are significantly easier to construct, as a black hole in an expanding cosmology requires the velocity function to change sign. Consequently, this work primarily examines white holes in expanding cosmologies as a foundation for subsequent analysis of black holes in expanding universes. In later sections, we investigate scenarios involving a white hole coupled with cosmological matter, as well as a white hole with both matter and a cosmological constant. Assuming the pressure component takes its cosmological value, we show that the physical radius of the apparent horizon can asymptotically approach a constant value at late times. This metric avoids pathologies such as a singular horizon in the limit of a vanishing Hubble parameter. Finally, we analyze the realistic case of a black hole embedded in pressureless cosmological matter with and without a cosmological constant and explore its properties.

[56] arXiv:2506.03695 (替换) [中文pdf, pdf, html, 其他]

标题： 静态共形 Killing 重力中黑洞的普遍热力学拓扑类别 显示英文标题

标题： Universal thermodynamic topological classes of static black holes in Conformal Killing Gravity

Hao Chen, Di Wu, Meng-Yao Zhang, Soroush Zare, Hassan Hassanabadi, Bekir Can Lütfüoğlu, Zheng-Wen Long

评论： 10页，14图

期刊参考： 欧洲物理杂志C 85 (2025) 828

主题： 广义相对论与量子宇宙学 (gr-qc)

在本研究中，我们开发了共形 Killing 引力背景下静态黑洞的通用热力学拓扑类别。 我们的研究结果表明，共形 Killing 引力显著重构了最小内部和最大外部黑洞态的热力学性质。 此外，它在高温和低温区域都显著改变了黑洞的热力学稳定性。 此分析显示，不同的 CKG 参数设置会导致带电 AdS 黑洞分为$W^{0+}$ $(\lambda>0)$ 和$W^{1+}$ $(\lambda<0)$ 类别，共形 Killing 引力中的 Reissner-Nordstr$\ddot{o}$m 黑洞被归类为$W^{0+}$和$W^{1+}$类别。 此外，我们考察了忽略电荷的特定情况。 该研究揭示，在共形杀戮引力框架下，类似于Schwarzschild-AdS黑洞的Schwarzschild黑洞可以被归类到$W^{1-}$和$W^{0-}$类别中。 这项工作为量子引力理论的基本性质提供了关键见解。 显示英文摘要

In this study, we develop universal thermodynamic topological classes for the static black holes in the context of the Conformal Killing Gravity. Our findings indicate that the Conformal Killing Gravity significantly reconstructs the thermodynamic properties of both the smallest inner and the largest outer black hole states. Additionally, it considerably alters the thermodynamic stability of black holes across both high-temperature and low-temperature regimes. This analysis shows that different CKG parameter settings will lead to $W^{0+}$ $(\lambda>0)$ and $W^{1+}$ $(\lambda<0)$ categories for the charged AdS black hole, the Reissner-Nordstr$\ddot{o}$m black hole in Conformal Killing Gravity is classified into the $W^{0+}$ and $W^{1+}$ categories. Furthermore, we examine the specific scenario where charge is neglected. The study reveals that within the framework of Conformal Killing Gravity, the Schwarzschild black hole similar to the Schwarzschild-AdS black hole, can be classified into the $W^{1-}$ and $W^{0-}$ categories. This work provides key insights into the fundamental nature of quantum gravity theory.

[57] arXiv:2507.01070 (替换) [中文pdf, pdf, html, 其他]

标题： 巴罗全息暗能量相互作用模型在辐射和物质存在下的情况 显示英文标题

标题： Barrow holographic dark energy interacting model in the presence of radiation and matter

Gopinath Guin, Souvik Paul, Sunandan Gangopadhyay

评论： 50页，40图，更新版本，欢迎提出意见

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

我们研究了在非平坦宇宙中的相互作用巴罗全息暗能量模型中动态辐射的影响。 对于开放和闭合宇宙，我们获得了七种可能的线性现象学相互作用中四种不同相互作用下暗能量、暗物质和辐射的能量密度参数的演化方程。 然后，我们数值求解这些耦合微分方程，以显示它们随红移参数的行为。 还展示了不同相互作用模型中暗能量状态方程参数随红移的动力学。 对于所有四种相互作用模型，还发现当巴罗指数较高时，暗能量状态方程参数在早期时间从快子区域过渡到幻影区域，即对于较低的红移值。 我们还发现了对应于暗能量-暗物质、暗能量-辐射和暗物质-辐射交叉的不同时期。 这些交叉点也与宇宙的热历史一致。 我们还使用宇宙时钟、重子声学振荡器和Pantheon+数据集，获得了我们相互作用巴罗全息暗物质模型中不同宇宙学参数的各种观测约束。 我们的宇宙学模型中哈勃参数的约束值比$\Lambda$CDM 模型更高，因此表明可能解决了哈勃张力问题。 显示英文摘要

We have studied the effect of dynamical radiation in the interacting barrow holographic dark energy model for a non-flat universe. For both open and closed universes, we have obtained the evolution equation for the energy density parameters for dark energy, dark matter and radiation for four different kinds of interaction among the seven possible linear phenomenological interactions. We have then numerically solved those coupled differential equations to show their behaviour with the redshift parameter. Also, the dynamics of the dark energy equation of state parameter with redshift for different interaction models are shown. For all four interaction models, it is also found that for higher values of the Barrow exponent, the dark energy equation of state parameter shows a transition into the phantom region from the quintessence region in the early time, that is, for lower redshift values. We have also found different epochs corresponding to dark energy-dark matter, dark energy-radiation and dark matter-radiation crossings. These crossing points are also consistent with the thermal history of the universe. We have also obtained various observational constraints for different cosmological parameters for our interacting Barrow holographic dark matter model using the Cosmic chronometer, Baryon Acoustic Oscillator and Pantheon+ data sets. The constraint values of the Hubble parameter in our cosmological shows higher values compared to the $\Lambda$CDM model, therefore indicating towards a possible resolution to the Hubble tension problem.

[58] arXiv:2507.05826 (替换) [中文pdf, pdf, html, 其他]

标题： 引力辐射在无限远处具有负宇宙学常数和AdS$_4$全息理论 显示英文标题

标题： Gravitational radiation at infinity with negative cosmological constant and AdS$_4$ holography

Francisco Fernández-Álvarez, José M. M. Senovilla

评论： 31页，2张图，新增参考文献和注释

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th) ; 数学物理 (math-ph)

在存在负宇宙常数的情况下，展示了穿过无限远的引力辐射存在的协变表征$\mathscr{J}$。它与之前针对非负宇宙常数情况提出的表征是一致且自洽的，依赖于渐近超-Poynting矢量的性质；或者更明确地说，基于无限远处潮汐能通量的内在性质。所提出的表征是完全令人满意的，它可以基于无限处的边界数据进行协变分类，并且也可以根据缩放后的Weyl张量在$\mathscr{J}$处的几何性质进行分类。没有来自（或没有逃逸至）$\mathscr{J}$的入射辐射的情况也可以根据边界数据或缩放后Weyl张量的几何性质来确定。特别是，我们确定了最一般的边界条件，在初始-边界值问题中，这些条件确保穿过$\mathscr{J}$的引力辐射不存在，即在$\mathscr{J}$处Cotton-York张量场与全息应力张量场之间的（函数）比例关系。我们还提出了新的条件，确保在$\mathscr{J}$处仅没有入射（或出射）辐射。这些条件是以协变方式给出的，并且也以标准缩放后的Weyl张量标量形式给出。结果与物理时空中的任何物质内容相容。 显示英文摘要

The covariant characterization of the existence of gravitational radiation traversing infinity $\mathscr{J}$ in the presence of a negative cosmological constant is presented. It is coherent and consistent with the previous characterizations put forward for the cases of non-negative cosmological constant, relying on the properties of the asymptotic super-Poynting vector; or in more transparent terms, based on the intrinsic properties of the flux of tidal energy at infinity. The proposed characterization is fully satisfactory, it can be covariantly typified in terms of boundary data at infinity, and it can also be categorized according to the geometric properties of the rescaled Weyl tensor at $\mathscr{J}$. The cases with no incoming radiation entering from (or no outgoing radiation escaping at) $\mathscr{J}$ can similarly be determined in terms of the boundary data or geometric properties of the rescaled Weyl tensor. In particular, we identify the most general boundary conditions that, in an initial-boundary value problem, ensure absence of gravitational radiation traversing $\mathscr{J}$, namely (functional) proportionality between the Cotton-York tensor field and the holographic stress tensor field at $\mathscr{J}$. We also present novel conditions ensuring the absence of just incoming (outgoing) radiation at $\mathscr{J}$. These are given in a covariant way and also in terms of standard rescaled Weyl tensor scalars. The results are compatible with any matter content of the physical spacetime.

[59] arXiv:2507.10028 (替换) [中文pdf, pdf, html, 其他]

标题： 黑洞相变的普适指数在零温极限下 显示英文标题

标题： Universal exponents of black hole phase transition at zero-temperature limit

Shao-Wen Wei, Shan-Ping Wu, Yu-Peng Zhang, Yu-Xiao Liu

评论： 5页，2图，小修，参考文献已添加

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

在本工作中，我们研究了黑洞相变在零温度极限下的普遍热力学特性。 我们的结果表明，在临界点以下远的地方，接近零温度的区域也表现出普遍性质。 通过采用麦克斯韦等面积定律并分析黑洞相变的共存曲线，我们推导出三个普遍指数：$\alpha=1$、$\beta=2$和$\gamma=d-3$，其中$d$表示时空维度数。 此外，进一步的研究表明，这些指数无论黑洞的电荷和自转如何都保持不变。 这些普遍指数为增强我们对零温度附近黑洞热力学相变的理解提供了有价值的见解，并揭示了量子引力的基本方面。 显示英文摘要

In this work, we investigate the universal thermodynamic characteristics of black hole phase transitions at the zero-temperature limit. Our results reveal that, far below the critical point, the near zero-temperature region also exhibits universal properties. By employing the Maxwell equal area law and analyzing the coexistence curve of black hole phase transitions, we derive three universal exponents: $\alpha=1$, $\beta=2$, and $\gamma=d-3$, where $d$ represents the spacetime dimension number. Furthermore, additional studies show that these exponents remain unchanged regardless of the black hole's charge and spin. These universal exponents provide valuable insights into enhancing our understanding of black hole thermodynamic phase transitions near zero temperature and shed light on the fundamental aspects of quantum gravity.

[60] arXiv:2507.10255 (替换) [中文pdf, pdf, html, 其他]

标题： FLRW视界热力学在爱因斯坦-高斯-博内特引力中 显示英文标题

标题： Thermodynamics of the FLRW apparent horizon in Einstein-Gauss-Bonnet gravity

Luis M. Sánchez, Hernando Quevedo

评论： 拼写错误已更正，添加了参考文献和注释

主题： 广义相对论与量子宇宙学 (gr-qc)

我们分析了爱因斯坦-高斯-博内特引力中弗里德曼-勒梅特-罗伯逊-沃尔克（FLRW）时空的表观视界的热力学性质。我们使用高维引力理论中熵的广义定义来确定主要的热力学变量，并将其行为与爱因斯坦理论中的相应量进行比较，强调高斯-博内特耦合常数和维度数的作用。通过施加热力学定律的有效性，我们表明表观视界可以被解释为一种暗能量流体，而无需考虑耦合常数和维度数。利用响应函数，我们确定了表观视界的绝热指数和热可访问自由度的数量，并认为这会导致高斯-博内特耦合常数的离散化。 显示英文摘要

We analyze the thermodynamic properties of the apparent horizon of Friedmann-Lema\^itre-Roberson-Walker (FLRW) spacetimes in Einstein-Gauss-Bonnet gravity. We use the generalized definition of entropy for gravity theories in higher dimensions to determine the main thermodynamic variables and to compare their behavior with the corresponding quantities in Einstein's theory, emphasizing the role of the Gauss-Bonnet coupling constant and the dimension number. By imposing the validity of the laws of thermodynamics, we show that the apparent horizon can be interpreted thermodynamically as a dark energy fluid, independently of the coupling constant and the dimension number. Using the response functions, we determine the adiabatic index and the number of thermally accesible degrees of freedom of the apparent horizon and argue that this leads to a discretization of the Gauss-Bonnet coupling constant.

[61] arXiv:2507.18397 (替换) [中文pdf, pdf, html, 其他]

标题： 时间延迟干涉测量配置的相关性和冗余性 显示英文标题

标题： Correlation and Redundancy of Time-Delay Interferometry Configurations

Gang Wang

评论： 18页，11图，系列相关作品的一部分： arXiv:2406.14173, arXiv:2403.01726, arXiv:2403.01490, arXiv:2406.11305, arXiv:2502.03983

主题： 广义相对论与量子宇宙学 (gr-qc) ; 天体物理学的仪器与方法 (astro-ph.IM)

时延干涉测量（TDI）对于基于空间的引力波（GW）任务至关重要，因为它可以抑制激光频率噪声并实现所需的灵敏度。 除了标准的迈克尔逊配置外，已经提出了各种第二代TDI方案，每个方案都利用了不同的星间激光链路组合。 在本工作中，我们对几种具有不同时间跨度的代表性TDI配置进行了比较研究，并证明它们的（准）正交信道高度相关，表明这些方案之间存在大量冗余。 在低频范围内，不同TDI配置的性能几乎相同。 它们的差异主要出现在高频区域，此时引力波波长与臂长相当。 在此区域内，具有较短TDI时间跨度且零频率最少的配置有助于在频域中更准确地进行波形建模和参数恢复。 相反，具有较长时间跨度和更多零频率的配置，如迈克尔逊配置，更容易受到频率混叠和波形调制效应的影响，从而降低推断精度。 然而，如果信号建模和分析是在时域中进行的，所有TDI配置将变得基本上等效。 考虑到在频域和时域中的可用性，具有较短跨度的PD4L方案表现出最少的零点，并且在高频区域性能优越，因此成为未来基于空间的GW任务设计的一个有前景的候选方案。 显示英文摘要

Time-Delay Interferometry (TDI) is essential for space-based gravitational wave (GW) missions, as it suppresses laser frequency noise and achieve the required sensitivity. Beyond the standard Michelson configuration, a variety of second-generation TDI schemes have been proposed, each utilizing different combinations of inter-spacecraft laser links. In this work, we conduct a comparative study of several representative TDI configurations with varying time spans and demonstrate that their (quasi-)orthogonal channels are highly correlated, indicating substantial redundancy among these schemes. In the low-frequency regime, the performance of different TDI configurations are nearly identical. Their distinctions emerge primarily at high frequencies, where the GW wavelength becomes comparable to the arm length. In this regime, shorter TDI time spans with minimal null frequencies facilitate more accurate waveform modeling and parameter recovery in frequency domain. In contrast, configurations with longer time spans and more null frequencies, such as the Michelson, are more susceptible to frequency aliasing and waveform modulation effects, which degrade inference accuracy. However, if signal modeling and analysis are performed in the time domain, all TDI configurations become effectively equivalent. Considering the usability in both frequency and time domain, the short-span PD4L scheme, which exhibits minimal nulls and superior performance in high frequencies, emerges as a promising candidate for future space-based GW mission designs.

[62] arXiv:2507.23475 (替换) [中文pdf, pdf, html, 其他]

标题： 旋转黑洞周围超辐射轴子场中的压缩引力子 显示英文标题

标题： Squeezed gravitons from superradiant axion fields around rotating black holes

Panagiotis Dorlis, Nick E. Mavromatos, Sarben Sarkar, Sotirios-Neilos Vlachos

评论： 45页，revtex格式，包含7张图表，错误已更正

主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th) ; 量子物理 (quant-ph)

我们在(3+1)维时空中，提出了一种新型的天体物理引力子压缩态来源，这是由于围绕旋转（Kerr型）黑洞（BH）的超辐射轴子云引起的。 这些轴子的微观起源多种多样，从卡拉布-拉蒙德（模型无关）轴子和弦理论中的紧致化轴子，到弦理论中由爱因斯坦-卡坦理论中扭曲几何所体现的\cm 完全反对称的挠率分量。 轴子场与有效引力作用中的手征规范和引力陈-西蒙斯（CS）异常项耦合。 在存在Kerr BH背景的情况下，这些轴子在获得质量后会导致超辐射，并产生一对纠缠的引力子压缩态。 只要轴子是具有质量的，其具体的微观起源并不重要。 通过量子光学中使用的类似塔卡吉分解方法，对这种多模压缩引力子态进行了研究。 在有效作用中表明，与传统广义相对论（GR）相关的压缩效应远远超过由CS引力异常项引起的相应效应。 对于黑洞轴子云足够长的寿命，我们发现可以通过GR效应产生显著的压缩（通过相对于适当真空的引力子平均数来量化）。 还明确地证明了当这些纠缠态以左右极化基表示时，其结构高度依赖于是GR效应还是异常的CS效应产生了纠缠。 显示英文摘要

We propose, in (3+1)-dimensional spacetimes, a novel astrophysical source of squeezed graviton states, due to superradiant axionic clouds surrounding rotating (Kerr-type) black holes (BH). The microscopic origin of these axions is diverse, ranging from the Kalb-Ramond (model-independent) axions and compactification axions in string theory, to \cm contorted geometries exemplified by a totally antisymmetric component of torsion in Einstein-Cartan theory. The axion fields couple to chiral gauge and gravitational Chern-Simons (CS) anomaly terms in the effective gravitational actions. In the presence of a Kerr BH background, such axions lead, upon acquiring a mass, to superradiance and the production of pairs of entangled gravitons in a squeezed state. The specific microscopic origin of the axions is not important, provided they are massive. This multimode squeezed-graviton state is examined through a Takagi-like decomposition, used in quantum optics. In the effective action it is shown that squeezing effects associated with conventional general relativity (GR) dominate, by many orders of magnitude, the corresponding effects due to the CS gravitational anomaly terms. For a sufficiently long lifetime of the axionic cloud of the BH, we find that significant squeezing (quantified through the average number of gravitons with respect to the appropriate vacuum) can be produced from the GR effects. It is also demonstrated explicitly that the structure of the entangled states (when the latter are expressed in a left-right polarization basis) depends highly on whether the GR or the anomalous CS effects produce the entanglement.

[63] arXiv:2307.04672 (替换) [中文pdf, pdf, html, 其他]

标题： 黑洞驱动的量子相干放大器 显示英文标题

标题： Black-hole powered quantum coherent amplifier

Avijit Misra, Pritam Chattopadhyay, Anatoly Svidzinsky, Marlan O. Scully, Gershon Kurizki

期刊参考： npj 量子信息 10.1，34 (2024)

主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

落入黑洞（BH）腔体中的原子被证明能够通过黑洞引力真空能实现光量子的相干放大。 此过程可以利用黑洞能量用于有用的目的，例如推动被黑洞困住的宇宙飞船。 该过程可以通过由部分被轨道镜反射的霍金辐射激发的下落原子对信号场的瞬时放大来实现。 在与场弱耦合的热平衡原子的稳态状态下，这种放大器构成了一种由黑洞供电的量子热机。 设想中的效应证实了将黑洞加速辐射作为热力学方法的理论。 显示英文摘要

Atoms falling into a black hole (BH) through a cavity are shown to enable coherent amplification of light quanta powered by the BH gravitational vacuum energy. This process can harness the BH energy towards useful purposes, such as propelling a spaceship trapped by the BH. The process can occur via transient amplification of a signal field by falling atoms that are partly excited by Hawking radiation reflected by an orbiting mirror. In the steady-state regime of thermally equilibrated atoms that weakly couple to the field, this amplifier constitutes a BH-powered quantum heat engine. The envisaged effects substantiate the thermodynamic approach to BH acceleration radiation.

[64] arXiv:2401.01743 (替换) [中文pdf, pdf, html, 其他]

标题： 紧邻LIGO-Virgo双黑洞合并的致密天体指示 显示英文标题

标题： Indication for a compact object next to a LIGO-Virgo binary black hole merger

Shu-Cheng Yang, Wen-Biao Han, Hiromichi Tagawa, Song Li, Chen Zhang

评论： 8页，6图

期刊参考： 天体物理期刊快报，988:L41，2025

主题： 高能天体物理现象 (astro-ph.HE) ; 广义相对论与量子宇宙学 (gr-qc)

双黑洞（BBH）合并的天体物理起源仍然不确定，尽管LIGO-Virgo-KAGRA网络已经观测到了许多事件。 这些合并可能起源于大质量黑洞（MBH）附近。 GW190814由于其次级质量和质量比超出了孤立恒星演化理论的预期，是一个发生在活动星系核（AGN）盘中的有希望的事件。 在这个模型中，一个致密天体位于合并的BBH附近。 在此，我们报告了多个证据，表明GW190814是靠近一个致密天体的BBH合并。 BBH围绕第三个天体的轨道运动会产生视线加速度（LSA），并引发变化的多普勒频移。 使用一个考虑LSA的波形模板，我们在引力波（GW）瞬变目录中对几个信噪比较高的BBH事件进行了贝叶斯推断。 与孤立BBH合并的模型相比，包括LSA后，我们获得了GW190814显著更高的网络信噪比，以$90 \%$置信度水平将LSA限制在$a = 0.0015^{+0.0008}_{-0.0008} ~c~\mathrm{s}^{-1}$。 此外，LSA情况相对于孤立情况的贝叶斯因子为$58/1$，表明GW数据强烈偏好LSA模型。 我们得出结论，这是首次表明合并的BBH位于第三个致密天体附近。 显示英文摘要

The astrophysical origin of binary black hole (BBH) mergers remains uncertain, although many events have been observed by the LIGO-Virgo-KAGRA network. Such mergers are potentially originated in the vicinity of massive black holes (MBHs). GW190814, due to its secondary mass and mass ratio being beyond the expectations of isolated stellar evolution theories, is a promising event that has occurred in an active galactic nucleus (AGN) disk. In this model, a compact object resides in the vicinity of a merging BBH. Here we report multiple pieces of evidence suggesting that GW190814 is a BBH merging near a compact object. The orbital motion of BBHs around a third body produces a line-of-sight acceleration (LSA) and induces a varying Doppler shift. Using a waveform template that considers LSA, we perform Bayesian inference on a few BBH events with a high signal-to-noise ratio in the gravitational-wave (GW) transient catalog. Compared to the model for isolated BBH mergers, we obtain significantly higher network signal-to-noise ratios for GW190814 with the inclusion of LSA, constraining the LSA to $a = 0.0015^{+0.0008}_{-0.0008} ~c~\mathrm{s}^{-1}$ at a $90 \%$ confidence level. Additionally, the Bayes factor for the LSA case over the isolated case is $58/1$, indicating that the GW data strongly prefer the LSA model. We conclude that this is the first indication showing merging BBHs are located near a third compact object.

[65] arXiv:2409.06479 (替换) [中文pdf, pdf, html, 其他]

标题： 带有周期时钟的关系动力学 显示英文标题

标题： Relational Dynamics with Periodic Clocks

Leonardo Chataignier, Philipp A. Hoehn, Maximilian P. E. Lock, Fabio M. Mele

评论： 32 + 16页，2个图。参考文献已更新，且有小的更正

主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

我们讨论了一种系统的方法，以在经典和量子理论中相对于周期性钟建立关系动力学，强调它们之间的相似之处。 我们表明：(1) 编码相对于周期性钟的量值的经典和量子关系可观测量，只有当该量本身是周期性的时候，才沿由哈密顿约束生成的规范轨道保持不变，否则这些可观测量仅在每个钟周期内暂时保持不变（这特别意味着，计数绕数不会导致相对于周期性钟的不变可观测量）；(2) 量子关系可观测量可以通过对单个钟周期进行部分群平均过程得到；(3) 基于狄拉克量子化时钟中性图景的量子关系可观测量、Page-Wootters形式主义的关系薛定谔图景以及从量子去参数化得出的关系海森堡图景之间的量子理论存在等价性（“三位一体”），所有三种都相对于周期性钟（这意味着所有三种中的动力学必然都是周期性的）；(4) 在周期性钟的背景下，原始的Page-Wootters条件概率定义对于具有连续能量谱的系统失效，并且使用Page-Wootters与钟中性、规范不变形式主义之间的等价性，必须对其进行适当更新。 最后，我们展示了相对于周期性钟周期演化的系统如何相对于非周期性钟单调演化，而不会产生不一致。 通过几个例子说明了这一表述，并以与其他处理周期性钟关系描述的文献方法的简要比较结束。 显示英文摘要

We discuss a systematic way in which a relational dynamics can be established relative to periodic clocks both in the classical and quantum theories, emphasising the parallels between them. We show that: (1) classical and quantum relational observables that encode the value of a quantity relative to a periodic clock are only invariant along the gauge orbits generated by the Hamiltonian constraint if the quantity itself is periodic, and otherwise the observables are only transiently invariant per clock cycle (this implies, in particular, that counting winding numbers does not lead to invariant observables relative to the periodic clock); (2) the quantum relational observables can be obtained from a partial group averaging procedure over a single clock cycle; (3) there is an equivalence ('trinity') between the quantum theories based on the quantum relational observables of the clock-neutral picture of Dirac quantisation, the relational Schr\"odinger picture of the Page-Wootters formalism, and the relational Heisenberg picture that follows from quantum deparametrisation, all three taken relative to periodic clocks (implying that the dynamics in all three is necessarily periodic); (4) in the context of periodic clocks, the original Page-Wootters definition of conditional probabilities fails for systems that have a continuous energy spectrum and, using the equivalence between the Page-Wootters and the clock-neutral, gauge-invariant formalism, must be suitably updated. Finally, we show how a system evolving periodically with respect to a periodic clock can evolve monotonically with respect to an aperiodic clock, without inconsistency. The presentation is illustrated by several examples, and we conclude with a brief comparison to other approaches in the literature that also deal with relational descriptions of periodic clocks.

[66] arXiv:2410.23837 (替换) [中文pdf, pdf, html, 其他]

标题： Nambu-Goldstone模在U(1)带电一阶相对论粘性流体力学中的模式分析 显示英文标题

标题： Mode analysis of Nambu-Goldstone modes in U(1) charged first-order relativistic viscous hydrodynamics

Atsuhisa Ota

评论： 49页，版式改进

主题： 高能物理 - 理论 (hep-th) ; 统计力学 (cond-mat.stat-mech) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 现象学 (hep-ph) ; 核理论 (nucl-th)

我们对平直闵可夫斯基时空中的广义$U(1)$-电荷一阶相对论流体动力学进行模式分析，其框架为耗散流体的有效场理论。 我们推导出包含随机噪声的最一般的流体动力学模式二次作用量，并在一致梯度展开中分析相应的色散关系。 我们认为，在由局部类时四矢量指定的局部热态存在时，时空对称性的自发破缺会出现。 我们证明流体动力学扰动可以被识别为Nambu-Goldstone(NG)模式，类似于它们在全局$U(1)$-不变理论中的嵌入。 我们发现，流体动力学输运系数的框架不变组合决定了低能极限下的第一阶色散关系，使得模式分析明显独立于流体动力学框架的选择。 假设局部Kubo-Martin-Schwinger(KMS)对称性和底层紫外理论的幺正性，我们表明如果焓密度为正，则第一阶流体动力学是稳定的。 显示英文摘要

We conduct a mode analysis of a general $U(1)$-charged first-order relativistic hydrodynamics within the framework of effective field theory for dissipative fluids in flat Minkowski spacetime. We derive the most general quadratic action for hydrodynamic modes, including stochastic noise, and analyze the corresponding dispersion relations in a consistent gradient expansion. We argue that spontaneous breaking of spacetime symmetry arises in the presence of a local thermal state specified by a local timelike four-vector. We demonstrate that hydrodynamical perturbations can be identified as Nambu-Goldstone (NG) modes, analogous to their embedding in global $U(1)$-invariant theories. We find that frame-invariant combinations of hydrodynamic transport coefficients determine the first-order dispersion relations in the low-energy limit, making the mode analysis manifestly independent of the choice of hydrodynamic frame. Assuming local Kubo-Martin-Schwinger (KMS) symmetry and unitarity of the underlying UV theory, we show that first-order hydrodynamics is stable if the enthalpy density is positive.

[67] arXiv:2501.02119 (替换) [中文pdf, pdf, html, 其他]

标题： 宇宙相关函数的大量平坦空间极限 显示英文标题

标题： The Massive Flat Space Limit of Cosmological Correlators

Sebastian Cespedes, Sadra Jazayeri

评论： 46页加上附录和14幅图

主题： 高能物理 - 理论 (hep-th) ; 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc)

识别宇宙学关联函数中有用的平空间极限，由于它们的尺度不变性，将其表示为闵可夫斯基空间中的可观测量是不明显的。 近年来，已经证明动量空间关联函数在解析延拓后其运动学复平面上出现的特定奇点中包含平空间振幅。 这种平空间极限是无质量的，因为振幅对应于相关平空间过程的紫外区域，其中内部传播子的质量实际上为零。 在本文中，我们引入了一种新的有质量平空间（MFS）极限，在这种极限下，相应平空间费曼图中的内部质量保持有限。 我们的提议适用于具有轻外部腿和重内部线的任意图，使用双标度极限。 在这种极限下，外部能量被视为独立变量，与传播子质量成反比趋于零，而传播子质量被发送到无穷大。 我们提出了一种通用的约简公式，将此极限下的图表示为平空间中截断的费曼图。 我们的发现强调了有质量费曼积分的丰富结构与涉及重场交换的宇宙学关联函数性质之间的深刻联系。 利用这个约简公式，我们在小声速范围内计算了来自重粒子的一环贡献对暴胀关联函数的影响，揭示了新的三阶谱形状。 我们发现的非高斯信号，在等边构型附近尤为明显，无法通过向单场暴胀的有效场论中添加局部项来再现。 相反，它们通过将预定的空间非局部算符纳入有效场论来捕捉。 显示英文摘要

Identifying useful flat-space limits for cosmological correlators, where they can be expressed in terms of observables in Minkowski space is nontrivial due to their scale-invariant nature. In recent years, it has been shown that momentum-space correlators encode flat-space amplitudes at specific singularities that emerge in the complex plane of their kinematics after analytical continuation. This flat-space limit is massless in the sense that the amplitude corresponds to the ultraviolet regime of the associated flat-space process, where the masses of the internal propagators are effectively zero. In this paper, we introduce a novel massive flat-space (MFS) limit, in which the internal masses in the corresponding flat-space Feynman graph remain finite. Our proposal applies to arbitrary graphs with light external legs and heavy internal lines, using a double-scaling limit. In this limit, the external energies, treated as independent variables, approach zero in inverse proportion to the propagator masses, which are sent to infinity. We present a general reduction formula that expresses diagrams in this limit in terms of amputated Feynman graphs in flat space. Our findings underscore the deep connections between the rich structure of massive Feynman integrals and the properties of cosmological correlators involving the exchange of heavy fields. Using this reduction formula, we compute sample one-loop contributions from heavy particles to inflationary correlators in the small sound-speed regime, revealing novel bispectrum shapes. The non-Gaussian signals we uncover, which are especially pronounced around the equilateral configuration, cannot be reproduced by adding local terms to the effective field theory of single-field inflation. Instead, they are captured by incorporating prescribed spatially non-local operators into the EFT.

[68] arXiv:2503.11758 (替换) [中文pdf, pdf, html, 其他]

标题： 中微子味变换在中子星合并中 显示英文标题

标题： Neutrino Flavor Transformation in Neutron Star Mergers

Yi Qiu, David Radice, Sherwood Richers, Maitraya Bhattacharyya

评论： 12页，8张图，被《物理评论快报》接受

主题： 高能天体物理现象 (astro-ph.HE) ; 广义相对论与量子宇宙学 (gr-qc)

我们展示了首次包含中微子味变换的数值相对论模拟，这些变换可能源于味不稳定性、量子多体效应或中子星合并中的标准模型之外的物理现象。 我们发现中微子味变换会影响残余物的组成和结构，可能会在并合后的引力波信号上留下印记。 它们还对喷射物的组成和核合成产量有显著影响。 显示英文摘要

We present the first numerical relativity simulations including neutrino flavor transformations that could result from flavor instabilities, quantum many-body effects, or potential beyond standard model physics in neutron star mergers. We find that neutrino flavor transformations impact the composition and structure of the remnant, potentially leaving an imprint on the post-merger gravitational-wave signal. They also have a significant impact on the composition and nucleosynthesis yields of the ejecta.

[69] arXiv:2503.14969 (替换) [中文pdf, pdf, html, 其他]

标题： 用自洽的再结合历史和观测数据约束轴对称 Bianchi 类型 I 模型 显示英文标题

标题： Constraining Axially Symmetric Bianchi Type I Model with Self-Consistent Recombination History and Observables

Boris Hoi-Lun Ng, Ming-Chung Chu

评论： 13页，5图；对齐已发表的PRD版本进行小幅度修改

主题： 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc)

最近的宇宙学测量表明宇宙可能存在各向异性。 因此，Bianchi I型模型作为标准弗里德曼-勒梅特-罗伯逊-沃尔克度规最简单的各向异性扩展已被广泛研究。 在本工作中，我们展示了在各向异性宇宙中复合历史应如何修改，并通过考虑零测地线推导可观测量。 然后，我们通过使用马尔可夫链蒙特卡洛方法，结合宇宙微波背景（CMB）中的声学尺度和重子声学振荡数据，以及本地测量的$H(z)$和潘顿超新星数据，对轴对称Bianchi I型模型进行约束。 我们的结果表明，与$\Lambda$冷暗物质模型相比，各向异性模型并不值得提及，我们得到了一个紧致的各向异性约束，该约束在最大温度各向异性分数为$2\times 10^{-5}$的情况下通常与之前的研究一致。 为了允许非运动学的CMB偶极子，我们还基于一个放松的最大温度各向异性进行了约束，该各向异性与CMB偶极子相当。 我们强调，当存在明显的各向异性时，基于测地线的可观测量与简单的各向同性类比之间存在显著差异。 然而，即使在放松的各向异性极限下，复合历史的变化也是不显著的。 显示英文摘要

Recent cosmological measurements suggest the possibility of an anisotropic universe. As a result, the Bianchi Type I model, being the simplest anisotropic extension to the standard Friedmann-Lema\^itre-Robertson-Walker metric has been extensively studied. In this work, we show how the recombination history should be modified in an anisotropic universe and derive observables by considering the null geodesic. We then constrain the axially symmetric Bianchi Type I model by performing Markov Chain Monte Carlo with the acoustic scales in Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillation data, together with local measurements of $H(z)$ and Pantheon Supernova data. Our results reveal that the anisotropic model is not worth a bare mention compared to the $\Lambda$ cold dark matter model, and we obtain a tight constraint on the anisotropy that generally agrees with previous studies under a maximum temperature anisotropy fraction of $2\times 10^{-5}$. To allow for a non-kinematic CMB dipole, we also present constraints based on a relaxed maximum temperature anisotropy comparable to that of the CMB dipole. We stress that there is a significant difference between the geodesic-based observables and the naive isotropic analogies when there is a noticeable anisotropy. However, the changes in recombination history are insignificant even under the relaxed anisotropy limit.

[70] arXiv:2504.01669 (替换) [中文pdf, pdf, 其他]

标题： 宇宙学宇宙白皮书：用系统性和基础物理解决宇宙学中的观测矛盾 显示英文标题

标题： The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics

Eleonora Di Valentino, Jackson Levi Said, Adam Riess, Agnieszka Pollo, Vivian Poulin, Adrià Gómez-Valent, Amanda Weltman, Antonella Palmese, Caroline D. Huang, Carsten van de Bruck, Chandra Shekhar Saraf, Cheng-Yu Kuo, Cora Uhlemann, Daniela Grandón, Dante Paz, Dominique Eckert, Elsa M. Teixeira, Emmanuel N. Saridakis, Eoin Ó Colgáin, Florian Beutler, Florian Niedermann, Francesco Bajardi, Gabriela Barenboim, Giulia Gubitosi, Ilaria Musella, Indranil Banik, Istvan Szapudi, Jack Singal, Jaume Haro Cases, Jens Chluba, Jesús Torrado, Jurgen Mifsud, Karsten Jedamzik, Khaled Said, Konstantinos Dialektopoulos, Laura Herold, Leandros Perivolaropoulos, Lei Zu, Lluís Galbany, Louise Breuval, Luca Visinelli, Luis A. Escamilla, Luis A. Anchordoqui, M.M. Sheikh-Jabbari, Margherita Lembo, Maria Giovanna Dainotti, Maria Vincenzi, Marika Asgari, Martina Gerbino, Matteo Forconi, Michele Cantiello, Michele Moresco, Micol Benetti, Nils Schöneberg, Özgür Akarsu, Rafael C. Nunes, Reginald Christian Bernardo, Ricardo Chávez, Richard I. Anderson, Richard Watkins, Salvatore Capozziello, Siyang Li, Sunny Vagnozzi, Supriya Pan, Tommaso Treu, Vid Irsic, Will Handley, William Giarè, Yukei Murakami, Adèle Poudou, Alan Heavens, Alan Kogut, Alba Domi, Aleksander Łukasz Lenart, Alessandro Melchiorri, Alessandro Vadalà, Alexandra Amon, Alexander Bonilla, Alexander Reeves, Alexander Zhuk, Alfio Bonanno, Ali Övgün, Alice Pisani, Alireza Talebian, Amare Abebe, Amin Aboubrahim, Ana Luisa González Morán, András Kovács, Andreas Papatriantafyllou, Andrew R. Liddle, Andreas Lymperis, Andronikos Paliathanasis, Andrzej Borowiec, Anil Kumar Yadav, Anita Yadav, Anjan Ananda Sen, Anjitha John William Mini Latha, Anne Christine Davis, Anowar J. Shajib, Anthony Walters

评论： 416页，81图

主题： 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 现象学 (hep-ph)

宇宙学的标准模型在过去几十年中为天体物理和宇宙学尺度上的广泛观测提供了一个良好的现象学描述。 这一协调模型由一个普遍的宇宙学常数构成，并由粒子物理的标准模型描述的物质部分以及冷暗物质贡献，以及非常早期的暴胀物理学支持，并通过广义相对论中的引力得到支撑。 标准模型的基础一直存在一些开放性问题。 然而，近年来表明，随着某些宇宙学探针之间的差异出现，观测领域也可能存在问题。 在本文中，我们确定了未来十年需要解决的关键目标，以及旨在应对这些挑战的核心科学项目。 这些分歧主要基于核心宇宙学参数测量的差异，具有不同水平的统计置信度。 这些可能的统计紧张关系可能部分可以通过各种测量或宇宙学探针中的系统误差来解释，但也出现了越来越多的迹象表明可能存在超出标准模型的新物理。 在回顾了用于测量宇宙学参数的主要探针以及潜在的系统误差后，我们讨论了可能在即将到来的调查中可观测到的最有希望的新物理阵列。 我们还讨论了越来越多的新型数据分析方法，这些方法超越了传统方法来测试物理模型。 [简要] 显示英文摘要

The standard model of cosmology has provided a good phenomenological description of a wide range of observations both at astrophysical and cosmological scales for several decades. This concordance model is constructed by a universal cosmological constant and supported by a matter sector described by the standard model of particle physics and a cold dark matter contribution, as well as very early-time inflationary physics, and underpinned by gravitation through general relativity. There have always been open questions about the soundness of the foundations of the standard model. However, recent years have shown that there may also be questions from the observational sector with the emergence of differences between certain cosmological probes. In this White Paper, we identify the key objectives that need to be addressed over the coming decade together with the core science projects that aim to meet these challenges. These discordances primarily rest on the divergence in the measurement of core cosmological parameters with varying levels of statistical confidence. These possible statistical tensions may be partially accounted for by systematics in various measurements or cosmological probes but there is also a growing indication of potential new physics beyond the standard model. After reviewing the principal probes used in the measurement of cosmological parameters, as well as potential systematics, we discuss the most promising array of potential new physics that may be observable in upcoming surveys. We also discuss the growing set of novel data analysis approaches that go beyond traditional methods to test physical models. [Abridged]

[71] arXiv:2504.02592 (替换) [中文pdf, pdf, html, 其他]

标题： 无质量自旋粒子的统一方程和新的自旋系数定义 显示英文标题

标题： Unified Equation for Massless Spin Particles and New Spin Coefficient Definitions

Zhong-Heng Li

评论： 28页

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)

无论研究极端质量比旋进产生的引力波，还是探索无质量自旋粒子波的类比，黑洞微扰理论都证明是不可或缺的。 在开发适用于此类问题的通用微扰框架的核心在于解决制定一个与坐标无关的、统一的波动方程的挑战，该方程应普遍适用于任何黑洞时空。 本文通过建立自旋系数的新定义，解决了类型-D时空中的这一核心问题。 具体来说，我们为自旋系数$\rho$、$\mu$、$\tau$和$\pi$引入了一个新定义，它们分别定义为生成函数的对数沿空四面体 ($l^{\mu}$、$n^{\mu}$、$m^{\mu}$、$\bar{m}^{\mu}$) 的方向导数。 这是首次发现这些自旋系数通过一个生成函数相互关联。 利用新定义的自旋系数，我们发现任意类型-D 黑洞时空中的自旋为 0、1/2、1、3/2 和 2 的无质量粒子的场方程可以通过一个统一的方程来描述。 这一发现尤其令人惊讶，因为在平直时空中统一这些场方程已经是一个重大的挑战，更不用说在黑洞周围的复杂时空中了。 因此，这项工作不可避免地会促使重新审视黑洞时空中各种粒子的共同特性。 同时，我们验证了自旋系数新定义的正确性，并给出了几乎所有已知类型-D 黑洞背景下的统一方程的显式形式。 这为研究任何类型-D 黑洞背景中无质量自旋粒子的行为奠定了坚实的基础。 显示英文摘要

Whether studying gravitational waves from extreme mass ratio inspirals or exploring the analogy between massless spin-particle waves, black hole perturbation theory proves indispensable. At the heart of developing a universal perturbation framework for such problems lies the challenge of formulating a coordinate-independent, unified wave equation that is universally applicable to any black hole spacetime. This paper resolves this central issue in type-D spacetimes by establishing a new definition of spin coefficients. Specifically, we introduce a new definition for the spin coefficients $\rho$, $\mu$, $\tau$, and $\pi$, which are defined as the directional derivatives of the logarithm of a generating function along the null tetrad ($l^{\mu}$, $n^{\mu}$, $m^{\mu}$, $\bar{m}^{\mu}$), respectively. This is the first discovery that these spin coefficients are interconnected through a generating function. Using the newly defined spin coefficients, we find that the field equations for massless particles with spins 0, 1/2, 1, 3/2, and 2 in arbitrary type-D black hole spacetimes can be described by a single unified equation. This finding is particularly surprising, as unifying these field equations is already a significant challenge in flat spacetime, let alone in the intricate spacetime around black holes. Consequently, this work will inevitably prompt a re-examination of the shared characteristics among various types of particles in black hole spacetimes. Meanwhile, we verify the correctness of the new definition for the spin coefficients, and provide the explicit form of the unified equation for nearly all known type-D black hole backgrounds. This lays a solid foundation for studying the behavior of massless spin particles in any type-D black hole background.

[72] arXiv:2504.05814 (替换) [中文pdf, pdf, html, 其他]

标题： 类型-II区域中PBH形成的阈值及其分析估计 显示英文标题

标题： The threshold for PBH formation in the type-II region and its analytical estimation

Albert Escrivà

评论： 8页和4幅图。v3：增加了附录和注释

主题： 宇宙学与非星系天体物理学 (astro-ph.CO) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)

我们数值模拟了在辐射主导的宇宙中，假设球对称性，由绝热扰动坍缩形成的原初黑洞（PBHs）的形成过程，针对不同的曲率轮廓$\zeta$。 我们的结果表明，PBH形成的阈值，定义为临界紧致函数$\mathcal{C}_{c}(r_m)$的峰值（其中$r_m$是峰值出现的尺度），在足够尖锐的轮廓下，并不会在I型区域渐近饱和到其最大可能值。 相反，该阈值出现在II型区域，其中$\mathcal{C}_{c}(r_m)$是一个最小值。 我们发现，在测试的情况下，这与在紧致函数$\mathcal{C}_{l}(r) \equiv -4r \zeta'(r)/3$的线性部分在其峰值$r_m$附近表现出极高曲率的轮廓（尖峰形状）有关。 为了在$r_m$处测量这种曲率，我们定义了一个无量纲参数：$\kappa \equiv -r^{2}_m \mathcal{C}_l''(r_m)$，并发现对于所使用的轮廓，类型-II区域中观察到的阈值发生在足够大的$\kappa$时。 通过用$\mathcal{C}_{l,c}(r_m)$来定义阈值，我们将之前的分析估计扩展到了类型-II区域，这在与测试轮廓的数值模拟比较时显示出几百分比内的准确性。 我们的结果表明，对于阈值位于类型-II区域的模型，当前PBH丰度计算可能由于普遍假设它应在类型-I和类型-II区域边界处饱和而被高估了。 显示英文摘要

We numerically simulate the formation of Primordial Black Holes (PBHs) in a radiation-dominated Universe under the assumption of spherical symmetry, driven by the collapse of adiabatic fluctuations, for different curvature profiles $\zeta$. Our results show that the threshold for PBH formation, defined as the peak value of the critical compaction function $\mathcal{C}_{c}(r_m)$ (where $r_m$ is the scale at which the peak occurs), does not asymptotically saturate to its maximum possible value in the type-I region for sufficiently sharp profiles. Instead, the threshold is found in the type-II region with $\mathcal{C}_{c}(r_m)$ being a minimum. We find, for the cases tested, that this is a general trend associated with profiles that exhibit extremely large curvatures in the linear component of the compaction function $\mathcal{C}_{l}(r) \equiv -4r \zeta'(r)/3$ shape around its peak $r_m$ (spiky shapes). To measure this curvature at $r_m$, we define a dimensionless parameter: $\kappa \equiv -r^{2}_m \mathcal{C}_l''(r_m)$, and we find that the thresholds observed in the type-II region occur for sufficiently large $\kappa$ for the profiles we have used. By defining the threshold in terms of $\mathcal{C}_{l,c}(r_m)$, we extend previous analytical estimations to the type-II region, which is shown to be accurate within a few percent when compared to the numerical simulations for the tested profiles. Our results suggest that current PBH abundance calculations for models where the threshold lies in the type-II region may have been overestimated due to the general assumption that it should saturate at the boundary between the type-I and type-II regions.

[73] arXiv:2507.12374 (替换) [中文pdf, pdf, html, 其他]

标题： 全天区搜索第四次LIGO-Virgo-KAGRA观测运行第一阶段的短时引力波爆发 显示英文标题

标题： All-sky search for short gravitational-wave bursts in the first part of the fourth LIGO-Virgo-KAGRA observing run

LIGO Scientific Collaboration, Virgo Collaboration, KAGRA Collaboration

评论： 29页，包括全部作者列表。数据文件已发布在 https://dcc.ligo.org/P2400601/public

主题： 高能天体物理现象 (astro-ph.HE) ; 广义相对论与量子宇宙学 (gr-qc)

我们在先进LIGO-Virgo-KAGRA第四次观测运行（称为O4a）前八个月的数据中进行持续时间较短的引力波瞬变信号搜索。我们使用四种分析方法，这些方法对在16-4096 Hz频段内持续几秒的潜在信号具有灵敏度。排除已由低延迟分析识别的双黑洞合并候选者后，我们没有发现其他引力波瞬变的统计显著证据。我们测量了对代表性信号的搜索灵敏度，包括正弦高斯信号、高斯脉冲和不同频率和持续时间的白噪声爆发，并采用每100年一次的误报率为检测阈值。根据信号类型，我们在应变幅度灵敏度和源密度上限方面比以前的搜索提高了2到10倍，置信度为90%。我们还评估了多种核心坍缩超新星模型，并发现对于某些模型，该搜索可能在整个银河系中探测到恒星核心坍缩的引力波。最后，我们考虑与脉冲星跳变相关的中子星f模，并发现假设源类似于Vela脉冲星，该搜索可能探测到频率变化比例小至$\sim 2$到$6 \times 10^{-5}$的跳变引力波信号，具体取决于中子星质量。 显示英文摘要

We present a search for short-duration gravitational-wave transients in data from the first eight months of Advanced LIGO-Virgo-KAGRA's fourth observing run, denoted O4a. We use four analyses which are sensitive to a wide range of potential signals lasting up to a few seconds in the 16-4096 Hz band. Excluding binary black hole merger candidates that were already identified by low-latency analyses, we find no statistically significant evidence for other gravitational-wave transients. We measure the sensitivity of the search for representative signals, including sine-Gaussians, Gaussian pulses, and white-noise bursts with different frequencies and durations, adopting a false alarm rate of 1 per 100 years as detection threshold. Depending on signal type, we find improvements over previous searches by factors of 2 to 10 in terms of sensitivity to strain amplitude and of 90% confidence upper limit on the rate density of sources. We also evaluate a variety of core-collapse supernova models and find that, for some models, the search could have detected gravitational waves from stellar core-collapse throughout the Milky Way. Finally, we consider neutron star f-modes associated with pulsar glitches and find that, assuming a source similar to the Vela Pulsar, the search could have detected a gravitational-wave signal from a glitch with fractional frequency change as small as $\sim 2$ to $6 \times 10^{-5}$ depending on the neutron star mass.

[74] arXiv:2507.13184 (替换) [中文pdf, pdf, html, 其他]

标题： 广义AdS高斯-博内-标量引力中的流体动力学输运 显示英文标题

标题： Hydrodynamical transports in generic AdS Gauss-Bonnet-scalar Gravity

Chenwei Tong, Rohit Mishra, Yanqi Wang, Song He

评论： 1+27页，无图表，参考文献已更新

主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 现象学 (hep-ph)

实验观察到的夸克-胶子等离子体（QGP）的温度依赖剪切粘度和体积粘度，以及其对Kovtun-Son-Starinets（KSS）界限$\eta/s=1/(4\pi)$的明显违反，需要一种包含高阶导数修正的全息描述。我们提出一个五维爱因斯坦-标量-麦克斯韦-高斯-博内模型，在该模型中，标量-高斯-博内耦合$H(\phi)$编码了主要的曲率修正。尽管没有闭合形式的黑洞解，我们通过事件视界处的熵产生分析，推导出了剪切粘度$\eta$和体积粘度$\zeta$的精确解析公式。这些表达式表现出对KSS界限的明显偏离和非平凡的温度依赖性。随后，我们通过滞后格林函数（Kubo）方法进行了独立计算，发现对于$\eta$完全一致，并在$\zeta$中隔离出一个需要数值确定的常数。我们的双重推导强调了高阶导数项在真实QGP建模中的关键作用，并展示了非解析全息背景在捕捉强耦合流体动力学方面的有效性。 显示英文摘要

The experimentally observed temperature-dependent shear and bulk viscosities of the quark-gluon plasma (QGP), along with its apparent violation of the Kovtun-Son-Starinets (KSS) bound $\eta/s=1/(4\pi)$, necessitate a holographic description that incorporates higher-derivative corrections. We propose a five-dimensional Einstein-Scalar-Maxwell-Gauss-Bonnet model in which a scalar-Gauss-Bonnet coupling $H(\phi)$ encodes leading curvature corrections. Although no closed-form black hole solution is available, we employ an entropy-production analysis at the event horizon to derive exact analytic formulas for the shear viscosity $\eta$ and bulk viscosity $\zeta$. These expressions exhibit apparent deviation from the KSS bound and nontrivial temperature dependence. We then perform an independent computation via the retarded Green function (Kubo) method, finding perfect agreement for $\eta$ and isolating a single constant in $\zeta$ that requires numerical determination. Our dual derivation underscores the pivotal role of higher-derivative terms in realistic QGP modeling and demonstrates the efficacy of nonanalytic holographic backgrounds in capturing the dynamics of strongly coupled fluids.