广义相对论与量子宇宙学
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- [1] arXiv:2508.04736 [中文pdf, pdf, html, 其他]
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标题： 在$f(R,L_{m},T)$引力理论中的具有引力波回声的致密星体标题： Compact stars with gravitational wave echoes in $f(R,L_{m},T)$ gravitational theory评论： 18页，16图主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)
这项工作探讨了在静态和球对称框架下的$f(R,L_{m},T)$引力背景中致密恒星结构的引力波回声（GWEs）。 我们的研究利用了MIT袋模型和颜色-味道锁定（CFL）相的状态方程（EoS）来描述物质。 质量-半径曲线是通过求解流体静力学平衡方程确定的。 在这里，通过改变模型参数来评估配置的稳定性。 TOV解有助于评估紧致性。 我们的结果表明，在$f(R,L_{m},T)$修正引力理论中的MIT袋模型和CFL EoS能够产生GWEs。 计算出的波频率位于$ 7.5-11 $千赫兹范围内。 我们还展示了在$f(R,L_{m},T)$理论内的不同引力理论参数化如何影响我们的恒星结构和回声频率特性。 表面红移和绝热指数分析证实了我们恒星模型的稳定性。
This work explores the gravitational wave echoes (GWEs) from the compact stellar configurations in the backdrop of $f(R,L_{m},T)$ gravity within static and spherically symmetric framework. Our study has utilized the MIT Bag model and color-favour-locked (CFL) phase equations of state (EoS) for matter description. Mass-radius profiles were determined by solving the hydrostatic equilibrium equations. Model parameter variations were used to assess the configuration stability here. TOV solutions helped to evaluate compactness. Our results indicate that MIT bag model and CFL EoS in $f(R,L_{m},T)$ modified gravitational theory are capable of producing GWEs. The calculated wave frequencies lie within the range of $ 7.5-11 $ kHz range. We have also demonstrated that how different gravitational theory parametrization within $f(R,L_{m},T)$ theory affect our star structure and echo frequency characteristics. Surface redshift and adiabatic index analysis confirm the stability of our stellar model here.
- [2] arXiv:2508.04738 [中文pdf, pdf, html, 其他]
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标题： 用红移依赖压强约束$f(Q,\mathcal{L}_{m})$引力：来自观测探针的见解标题： Constraining $f(Q,\mathcal{L}_{m})$ gravity with redshift-dependent pressure: Insights from observational probes评论： 15页，7图主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)
我们探讨在$f(Q,\mathcal{L}_{m})$引力框架下宇宙的晚期宇宙学动力学，通过考虑特定形式$f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$。为了描述宇宙压强的演化，引入了$p(z)=\alpha+\frac{\beta z}{1+z}$的红移依赖参数化。 MCMC分析使用来自哈勃（$46$个点）、BAO（$15$个点，包括DESI DR2）和Pantheon$+$（$1701$个Ia型超新星）的综合数据集，模型参数被约束为$H_{0}=67.9476^{+0.7534}_{-0.7523}$（km/s/Mpc），$\alpha=-0.0002^{+0.0211}_{-0.0208}$，$\beta=-0.0001^{+0.0410}_{-0.0404}$和$\gamma=0.0002^{+0.0599}_{-0.0602}$。 模型预测在$z_{tr} \approx 0.493$处出现从减速到加速的转变，当前值为$q_{0}=-0.255$和$\omega_{0}=-0.9001$。 能量密度和压强的演化符合观测预期。 能量条件分析表明 NEC 和 DEC 得到满足，而 SEC 被违反，这与晚期宇宙加速一致。 此外，慢滚参数$\epsilon_{1}$和$\epsilon_{2}$确认了一个平滑的暴胀时期。 这些结果展示了该模型统一早期宇宙暴胀与当前宇宙加速阶段的能力。
We explore the late time cosmological dynamics of the Universe within the framework of $f(Q,\mathcal{L}_{m})$ gravity by considering the specific form $f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$. To describe the cosmic pressure evolution, a redshift dependent parametrization of $p(z)=\alpha+\frac{\beta z}{1+z}$ is introduced. MCMC analysis is performed using a combined datasets from Hubble ($46$ points), BAO ($15$ points including DESI DR2) and Pantheon$+$ ($1701$ SNe Ia), the model parameters are constrained as $H_{0}=67.9476^{+0.7534}_{-0.7523}$ (km/s/Mpc), $\alpha=-0.0002^{+0.0211}_{-0.0208}$, $\beta=-0.0001^{+0.0410}_{-0.0404}$ and $\gamma=0.0002^{+0.0599}_{-0.0602}$. The model predicts a transition from deceleration to acceleration at $z_{tr} \approx 0.493$ with present values $q_{0}=-0.255$ and $\omega_{0}=-0.9001$. The evolution of energy density and pressure aligns with observational expectations. An analysis of energy conditions shows that NEC and DEC are satisfied, while SEC is violated, consistent with late time acceleration. Moreover, the slow roll parameters $\epsilon_{1}$ and $\epsilon_{2}$ confirm a smooth inflationary regime. These results demonstrate the capability of the model to unify early Universe inflation with the current phase of cosmic acceleration.
- [3] arXiv:2508.04744 [中文pdf, pdf, html, 其他]
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标题： 暗能量-猫头鹰转换在中子星各向异性Kiselev模型中的研究标题： Quintessence-Chameleon transitions in anisotropic Kiselev model of neutron stars评论： 42页，3个附录期刊参考： 《现代物理学期刊 A》，2550112（42 页），2025主题： 广义相对论与量子宇宙学 (gr-qc)
我们研究一种与Kiselev型度规动态相互作用的类变色龙标量场，其中度规的静态各向异性流体部分被一个与密度相关的标量场取代，该标量场非最小地耦合到曲率。这种构造使得在高密度区域表现出屏蔽行为——此时标量场获得有效质量m_\phi \propto \rho ^1/2——而在大尺度上表现出未屏蔽的第五元素动力学，其特征是临界屏蔽半径r_\rm crit\propto m_\phi ^-1。 通过在球对称条件下求解修改后的TOV方程，我们表明径向标量梯度\partial _r\phi 在中子星包层中引起压强各向异性\Delta p\propto r^-1，而偏离广义相对论的效应在核心深处 r<r_\rm crit\sim 0.03 \mathrm{km} 被抑制，而不会使其不稳定。 我们进一步证明，增加标量耦合\beta 会增强标量能量密度，这抵消了各向异性压力支撑并略微降低了最大质量。 产生的（稳定）配置的最大质量 M_max\approx 1.75\pm 0.280 M_\odot 和半径 R\approx 11.35\pm 1.11 \mathrm{km}，与多信使观测的保守上下限一致。 标量贡献在无量纲潮汐变形率\Lambda _\rm ST\Lambda _\rm GR\sim 0.137 在1.4 M_\odot 即，与典型GR星相比抑制了86%，远在LIGO/Virgo的范围70\lesssim \Lambda _1.4\lesssim 580之内。 这些结果表明，经过环境筛选的标量场可以动态地产生各向异性并修改中子星结构，而不会违反当前的天体物理限制。 特别是，致密性与潮汐响应中的百分比级偏差提供了短程标量力的可证伪特征，为下一代引力波和多信使调查提供了新的目标。
We investigate a chameleon scalar field dynamically interacting with a Kiselev-type metric, where the static anisotropic fluid part of the metric is replaced by a density-dependent scalar field non-minimally coupled to curvature. This construction enables a transition from screened behavior in high-density regions-where the scalar acquires an effective mass m_\phi\propto\rho^1/2-to unscreened quintessence dynamics at large scales, characterized by a critical screening radius r_\rm crit\propto m_\phi^-1. By solving the modified TOV equations under spherical symmetry, we show that radial scalar gradients \partial_r\phi induce pressure anisotropies \Delta p\propto r^-1 in neutron star envelopes, while deviations from general relativity are suppressed deep in the core r<r_\rm crit\sim 0.03\,\mathrm{km} without destabilizing it. We further demonstrate that increasing the scalar coupling \beta enhances scalar energy density, which counteracts anisotropic pressure support and slightly reduces the maximum mass. The resulting (stable) configurations yield maximum mass M_max\approx 1.75\pm0.280\,M_\odot and radii R\approx11.35\pm1.11\,\mathrm{km}, consistent with conservative upper and lower bounds from multimessenger observations. Scalar contributions induce a modest suppression in the dimensionless tidal deformability \Lambda_\rm ST\Lambda_\rm GR\sim0.137 at 1.4\,M_\odot i.e, 86% suppression compared to typical GR star, falling well within the LIGO/Virgo range 70\lesssim\Lambda_1.4\lesssim 580. These results demonstrate that environmentally screened scalar fields can dynamically generate anisotropies and modify neutron star structure without violating current astrophysical bounds. In particular, percent-level deviations in compactness and tidal response provide falsifiable signatures of short-range scalar forces, offering a novel target for next-generation GW and multimessenger surveys.
- [4] arXiv:2508.04758 [中文pdf, pdf, html, 其他]
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标题： 四标量模型和$f({\cal T})$理论中的球对称解标题： Four-scalar model and spherically symmetric solution in $f({\cal T})$ theory期刊参考： 核物理杂志B 1018 (2025) 116993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，我们研究了在修改的遥测引力框架内球对称解的构造，特别关注$f({\cal T})$理论，其中${\cal T}$表示扭力标量。常规的模仿引力及其具有两个标量场的扩展无法在$f({\cal T})$引力中再现一般的球对称几何，因为一致性要求扭力标量为常数或$f({\cal T})$的线性形式，这对应于广义相对论的遥测等价（TEGR）。为了克服这一限制，我们引入了一个四标量场公式，该公式推广了两标量模型，并能够实现任意的球对称时空。我们进一步证明，通过拉格朗日乘子施加适当的约束，该模型可以避免鬼魂自由度。作为该形式的的应用，我们检查了一个特定的球对称度规，并确定相应的四个标量场，分析它们的性质。在作用量的二次扩展${\cal T} + \tfrac{\alpha}{2}{\cal T}^2$存在的情况下，我们的方法成功地重建了无鬼魂不稳定的物理可行解。这些发现突显了基于标量场的构造在修改引力理论中生成一致时空几何的潜力，从而超越了标准形式。
In this work, we investigate the construction of spherically symmetric solutions within the framework of modified teleparallel gravity, focusing in particular on $f({\cal T})$ theory, where ${\cal T}$ represents the torsion scalar. Conventional mimetic gravity and its extension with two scalar fields are unable to reproduce general spherically symmetric geometries in $f({\cal T})$ gravity, since consistency requires either a constant torsion scalar or a linear form of $f({\cal T})$, which corresponds to the teleparallel equivalent of General Relativity (TEGR). To overcome this restriction, we introduce a four-scalar field formulation that generalizes the two-scalar model and enables the realization of arbitrary spherically symmetric spacetimes. We further demonstrate that the model avoids ghost degrees of freedom by imposing appropriate constraints through Lagrange multipliers. As an application of the formalism, we examine a specific spherically symmetric metric and determine the corresponding four scalar fields, analyzing their properties. In the presence of a quadratic extension of the action, ${\cal T} + \tfrac{\alpha}{2}{\cal T}^2$, our approach successfully reconstructs physically viable solutions free from ghost instabilities. These findings highlight the potential of scalar-field-based constructions for generating consistent spacetime geometries in modified gravity theories, thereby extending beyond the standard formulations.
- [5] arXiv:2508.04783 [中文pdf, pdf, html, 其他]
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标题： Vlasov气体向Kerr黑洞的吸积标题： Accretion of a Vlasov gas by a Kerr black hole评论： 38页，含19幅带说明的图主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能天体物理现象 (astro-ph.HE) ; 数学物理 (math-ph)
我们研究了无碰撞相对论性气体在旋转Kerr黑洞上的吸积过程，假设在无限远处气体的状态由仅依赖于粒子能量的分布函数描述。 忽略气体的自引力，我们表明相关的物理可观测量，包括粒子电流密度以及与质量、能量和角动量相关的吸积率，可以表示为闭合积分的形式，这些积分可以数值计算或在慢旋转极限下进行解析近似。 通过这种方式计算了单能粒子和Maxwell-Jüttner分布的吸积率，并与非旋转情况下的相应结果进行了比较。 虽然显示角动量吸积率恰好为零，但发现黑洞的旋转对质量和能量吸积率有微小但非零的影响，这种影响在旋转参数的二次近似下通过解析计算得到了非常准确的描述。 还分析了旋转对吸积流形态的影响。
We investigate the accretion of a collisionless, relativistic kinetic gas by a rotating Kerr black hole, assuming that at infinity the state of the gas is described by a distribution function depending only on the energy of the particles. Neglecting the self-gravity of the gas, we show that relevant physical observables, including the particle current density and the accretion rates associated with the mass, the energy, and the angular momentum, can be expressed in the form of closed integrals that can be evaluated numerically or approximated analytically in the slow-rotation limit. The accretion rates are computed in this manner for both monoenergetic particles and the Maxwell-J\"uttner distribution and compared with the corresponding results in the non-rotating case. Whereas it is shown that the angular momentum accretion rate vanishes exactly, it is found that the rotation of the black hole has a small but non-vanishing effect on the mass and the energy accretion rates, which is remarkably well described by an analytic calculation in the slow-rotation approximation to quadratic order in the rotation parameter. The effects of rotation on the morphology of the accretion flow are also analyzed.
- [6] arXiv:2508.04810 [中文pdf, pdf, html, 其他]
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标题： 尺度依赖引力的后牛顿展开标题： Post-Newtonian expansion of scale-dependent gravity评论： 12页主题： 广义相对论与量子宇宙学 (gr-qc)
尺度依赖的引力是广义相对论的一种扩展，在这种理论中，牛顿常数和宇宙学常数可能由于剩余的低能量子效应而在不同能量尺度上略有变化。这种方法的一个基本特征是尺度设定过程。在作者之一之前的工作中，建立了一个与守恒定律一致的尺度协变表达式。在这里，我们将完整的Will-Nordtvedt版本的参数化后牛顿（PPN）形式主义应用于这个框架，假设常数可以表示为尺度的幂级数。我们发现，在第一后牛顿阶次出现了一个新的势，这在标准的PPN形式主义中是不存在的。这个势修改了压力和内能的定义，但不影响质心轨道，因此不受太阳系测试的约束。
Scale-dependent gravity is an extension of general relativity in which the Newton and cosmological constants may vary slightly with the energy scale due to remnant low-energy quantum effects. A fundamental feature of this approach is the scale-setting procedure. In a previous work by one of the authors, a covariant expression for the scale, consistent with conservation laws, was established. Here, we apply the full Will-Nordtvedt version of the parameterized post-Newtonian (PPN) formalism to this framework, assuming that the constants can be expressed as a power series in the scale. We find that a new potential arises at the first post-Newtonian order, which is absent from the standard PPN formalism. This potential modifies the definitions of pressure and internal energy but does not affect center-of-mass orbits and is, therefore, not constrained by Solar System tests.
- [7] arXiv:2508.04817 [中文pdf, pdf, html, 其他]
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标题： 关于仿射空间中的Kaluza-Klein几何理论标题： On the Kaluza-Klein geometric theory in affine spaces评论： Revtex4-2 格式，25 页，1 图主题： 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) ; 微分几何 (math.DG)
在这项工作中，我们通过考虑纯粹的仿射框架，发展了Kaluza-Klein理论的一个推广，而无需假设先验的度量结构。 我们利用主纤维丛的几何学和Ehresmann联络来表述维度约化，引入适应性基底，使得张量、向量和联络能够显式分解。 这种形式主义为电磁场提供了一个自然的几何定义，即水平空间与观察者框架生成的空间之间的差异。 我们证明了非平凡电磁场的存在要求水平分布的不可积性，并推导出将仿射联络分解为在约化空间上定义的场的完整假设。 在假设如零扭转、测地线纤维和适当的归一化条件的情况下，我们表明约化理论对应于纯辐射电磁场的爱因斯坦-麦克斯韦系统。 此外，我们提出一种解释，其中度量通过电磁场的动力学从仿射结构中动态产生。
In this work, we develop a generalization of Kaluza-Klein theory by considering a purely affine framework, without assuming a prior metric structure. We formulate the dimensional reduction using the geometry of principal fiber bundles and the Ehresmann connection, introducing adapted bases that allow an explicit decomposition of tensors, vectors, and connections. This formalism provides a natural geometric definition of the electromagnetic field as the difference between the horizontal space and the space generated by the observer's frame. We demonstrate that the presence of a nontrivial electromagnetic field requires the non-integrability of the horizontal distribution, and we derive a complete ansatz for decomposing the affine connection into fields defined on the reduced space. Under assumptions such as vanishing torsion, autoparallel fibers, and suitable normalization conditions, we show that the reduced theory corresponds to the Einstein-Maxwell system for purely radiative electromagnetic fields. Furthermore, we propose an interpretation where the metric emerges dynamically from the affine structure through the dynamics of the electromagnetic field.
- [8] arXiv:2508.04850 [中文pdf, pdf, html, 其他]
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标题： 带有非对齐电磁场的新一类旋转带电黑洞标题： A new class of rotating charged black holes with non-aligned electromagnetic field评论： 57页，5图主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能物理 - 理论 (hep-th)
我们提出了一类大范围的扭动和扩展解，这些解是代数类型D的爱因斯坦-麦克斯韦方程的解，其中威伊尔张量的两个双重主null方向（PNDs）不与法拉第张量的null本征方向对齐。除了系统地推导出这个新类外，我们还给出了它的各种度规形式和方便的参数化方法。我们表明，在Boyer-Lindquist类型的坐标中，这些解依赖于7个参数，即Kerr和NUT（Newman-Unti-Tamburino）扭动参数$a$和$l$，质量参数$m$，加速度$\alpha$，麦克斯韦场强度$|c|$，以及角参数$\beta, \gamma$，这些参数表示法拉第张量的两个对偶旋转，包括生成麦克斯韦场对齐部分的电荷和磁荷之间的旋转。这种坐标参数化类似于Plebański-Demiański解的Griffiths-Podolský形式，使我们能够进行各种极限，明确识别子情况，并确定新类的物理解释。 有趣的是，通过考虑无加速度的极限（$\alpha\to 0$），可以得到著名的Kerr-Newman-NUT黑洞（如果参数$|c|$保持不变）或者新颖的Kerr-Bertotti-Robinson黑洞，这在我们最近的工作arXiv:2507.05199中已宣布（如果$|c|\rightarrow \infty$而$\alpha |c|=\mathrm{const.}$）。因此，我们可以得出结论，这个新的时空类代表了旋转带电的加速黑洞，处于外部磁场（或电场）中。在非旋转子情况中，我们得到了Alexeev-Garcia和Van den Bergh-Carminati之前已知的解。
We present a large family of twisting and expanding solutions to the Einstein-Maxwell equations of algebraic type D, for which the two double principal null directions (PNDs) of the Weyl tensor are not aligned with the null eigendirections of the Faraday tensor. In addition to systematically deriving this new class, we present its various metric forms and convenient parameterizations. We show that in Boyer-Lindquist-type coordinates these solutions depend on 7 parameters, namely the Kerr and NUT (Newman-Unti-Tamburino) twist parameters $a$ and $l$, mass parameter $m$, acceleration $\alpha$, strength of the Maxwell field $|c|$, and angular parameters $\beta, \gamma$ that represent two duality rotations of the Faraday tensor, which include the rotation between the electric and magnetic charges generating the aligned part of the Maxwell field. This coordinate parameterization, analogous to the Griffiths-Podolsk\'y form of the Pleba\'nski-Demia\'nski solutions, allows us to perform various limits, explicitly identify the subcases, and determine the physical interpretation of the new class. Interestingly, by considering the limit with no acceleration ($\alpha\to 0$), one obtains either the famous Kerr-Newman-NUT black holes (if the parameter $|c|$ remains constant) or the novel Kerr-Bertotti-Robinson black holes, announced recently in our work arXiv:2507.05199 (if $|c|\rightarrow \infty$ while $\alpha |c|=\mathrm{const.}$). We may thus conclude that this new class of spacetimes represents twisting charged accelerating black holes, immersed in an external magnetic (or electric) field. In the non-twisting subcase, we obtain the previously known solutions of Alexeev-Garcia and Van den Bergh-Carminati.
- [9] arXiv:2508.05018 [中文pdf, pdf, html, 其他]
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标题： 搜索具有有效单体模板的偏心双黑洞引力波标题： Search for gravitational waves from eccentric binary black holes with an effective-one-body template评论： 11页，5图，1表。数据发布在https://github.com/gwastro/O3-eccentricBBH-search。欢迎提出意见！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) ; 高能天体物理现象 (astro-ph.HE) ; 天体物理学的仪器与方法 (astro-ph.IM)
随着引力波天文学进入常规探测的时代，精确测量单个事件的物理参数并推断种群特性变得越来越重要。 偏心率是一个关键的可观测量，表明双星系统是在致密恒星环境中通过动力学相遇形成的。 这项工作首次使用一种新开发的有效一体化波形模型，对来自偏心双黑洞（BBH）的引力波进行了匹配滤波搜索，覆盖质量范围为$[5, 200]~M_\odot$且在20 Hz时偏心率高达0.5。 在整个第三轮观测运行中，LIGO、Virgo和KAGRA识别出28个BBH事件，误报率低于每100年一次；其中所有事件之前都在GWTC-3和4-OGC目录中报告过。 还报告了一些误报率在每1年至100年之间的额外候选事件。 我们进行了一次注入活动，以表征我们搜索流程的敏感体积时间。 假设之前的搜索没有遗漏任何偏心BBH事件，我们的结果对质量范围[5, 30]$M_\odot$内的偏心BBH事件率提供了限制。 对于一个30-30$M_\odot$的BBH，偏心率为0.5，事件率被限制为小于0.06 Gpc$^{-3}$年$^{-1}$；这相比之前不使用模板且建模最少的算法搜索，敏感体积有了一个数量级的改进。
As gravitational wave astronomy has entered an era of routine detections, it becomes increasingly important to precisely measure the physical parameters of individual events and infer population properties. Eccentricity is a key observable, suggesting that binaries form in a dense stellar environment through dynamical encounters. This work performs the first matched-filtering search for gravitational waves from eccentric binary black holes (BBHs) covering the mass range $[5, 200]~M_\odot$ and eccentricity at 20 Hz up to 0.5 with a newly developed effective-one-body waveform model. Throughout the third observation run of LIGO, Virgo, and KAGRA, we identify 28 BBH events with a false alarm rate below once per 100 yr; all of which were previously reported in the GWTC-3 and 4-OGC catalogs. Additional candidates with false alarm rates between once per 1 and 100 yr are also reported. We perform an injection campaign to characterize the sensitive volume time of our search pipeline. Assuming that none of the eccentric BBH events were missed by previous searches, our results provide constraints on the event rate of eccentric BBHs in the mass range [5, 30] $M_\odot$. For a 30-30 $M_\odot$ BBH with eccentricity 0.5, the event rate is limited to less than 0.06 Gpc$^{-3}$ yr$^{-1}$; this marks an order of magnitude improvement for sensitive volume compared with the previous search with a minimally modeled algorithm without using templates.
- [10] arXiv:2508.05218 [中文pdf, pdf, html, 其他]
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标题： 无源三维共形Killing引力中的黑洞和虫洞标题： Black holes and wormholes in sourceless three-dimensional conformal Killing gravity评论： 16页主题： 广义相对论与量子宇宙学 (gr-qc)
我们推导出具有两个Killing向量的三维共形Killing引力的所有无源解。 除了奇异解和BTZ黑洞外，平稳解还包括规则的扭曲AdS3黑洞和虫洞。
We derive all the sourceless solutions of three-dimensional conformal Killing gravity with two Killing vectors. Along with singular solutions and BTZ black holes, the stationary solutions include regular warped AdS3 black holes and wormholes.
- [11] arXiv:2508.05245 [中文pdf, pdf, html, 其他]
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标题： 非线性电动力学黑洞对周期轨道引力波形的影响标题： Nonlinear electrodynamic black hole's impact on the gravitational waveforms from periodic orbits评论： 12页，9图和2表主题： 广义相对论与量子宇宙学 (gr-qc)
在本文中，我们在非线性电动力学（NED）的框架下，研究围绕磁荷黑洞（MCBH）的展示zoom-whirl行为的周期轨道。我们检查NED电荷参数如何通过修改背景时空几何来影响轨道动力学，从而影响粒子的能量和角动量。特别是，我们计算了临界束缚轨道（MBOs）和最内稳定圆轨道（ISCOs）的半径，证明NED电荷参数会减小这两个半径。这为电荷参数在塑造轨道行为和改变时空几何中的作用提供了有价值的见解。我们将一个恒星级物体的复杂运动建模为一个类时粒子，在MCBH背景下螺旋进入超大质量黑洞（SMBH），其轨迹使用周期测地线轨道进行描述。基于对这些周期轨道的分析，我们进一步分析了极端质量比旋入（EMRIs）产生的引力波形，其中SMBH的时空主导了恒星级物体的动力学。通过将粒子轨迹分析与半解析的波形建模相结合，我们表明来自NED的电荷参数显著改变了zoom-whirl轨道动力学，并在波形结构中引起了明显的变化。这些结果说明未来的引力波（GW）观测可能限制MCBH的特性，从而加深我们对非线性电动力学引力印记的理解。
In this paper, we investigate periodic orbits exhibiting zoom-whirl behavior around a magnetically charged black hole (MCBH) within the framework of nonlinear electrodynamics (NED). We examine how the NED charge parameter influences orbital dynamics by modifying the background spacetime geometry, thereby affecting the energy and angular momentum of particles. In particular, we calculate the radii of the marginally bound orbits (MBOs) and innermost stable circular orbits (ISCOs), demonstrating that the NED charge parameter reduces both radii. This provides valuable insight into the role of the charge parameter in shaping orbital behavior and altering spacetime geometry. We model the complex motion of a stellar-mass object, as a timelike particle, inspiraling into a supermassive black hole (SMBH) in the MCBH background, with its trajectory described using periodic geodesic orbits. Based on this analysis of such periodic orbits, we further analyze the gravitational waveforms generated by extreme mass ratio inspirals (EMRIs), in which the SMBH's spacetime dominates the dynamics of the stellar-mass object. By combining particle trajectory analysis with waveform modeling in a semi-analytical, we show that the charge parameter arising from NED significantly alters the zoom-whirl orbital dynamics and induces notable changes in the waveform structure. These results illustrate that future gravitational wave (GW) observations may constrain the properties of MCBHs, thereby deepening our understanding of the gravitational imprint of nonlinear electrodynamics.
- [12] arXiv:2508.05326 [中文pdf, pdf, html, 其他]
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标题： 高阶导数引力理论中黑洞的欧几里得积分之间的普遍关系标题： A universal relation among Euclidean integrals for black holes in higher-derivative gravity theories评论： 8页，无图主题： 广义相对论与量子宇宙学 (gr-qc)
在本文中，我们建立了一个普遍的等式，用于描述高阶导数理论中引力作用的欧几里得积分。 该关系被证明对于纯引力中的渐近平坦黑洞是普遍成立的，并通过适当的正则化推广到渐近反德西特（AdS）时空。 我们进一步检验了其在物质-引力耦合系统中的有效性，确定只有当物质场表现出病态行为时才会出现违反情况：在视界处发散或在无限远处不衰减的分布。 这些发现揭示了引力热力学的基本约束，并提供了识别不良物质配置的诊断工具。
In this paper, we establish a universal equality governing Euclidean integrals of gravitational actions in higher-derivative theories. This relation is shown to hold universally for asymptotically flat black holes in pure gravity, and is generalized to asymptotically anti-de Sitter (AdS) spacetimes through appropriate regularization. We further examine its validity in systems with matter-gravity coupling, identifying that violations occur only when matter fields exhibit pathological behaviors: divergence at the horizon or non-decaying profiles at infinity. These findings reveal fundamental constraints on gravitational thermodynamics and provide diagnostic tools for identifying ill-behaved matter configurations.
- [13] arXiv:2508.05536 [中文pdf, pdf, html, 其他]
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标题： 非定态虫洞，存在标量场和修改引力的情况标题： Non-stationary wormholes with the presence of scalar fields and modified gravity评论： 13页，欢迎提出意见主题： 广义相对论与量子宇宙学 (gr-qc)
一些新颖的正则时空被考虑，这些时空表现出非稳态虫洞结构。 应用了类似Simpson-Visser的过程来重建这些正则时空，这些时空没有类时和类空奇点。 该过程也用于描述一种正则宇宙膨胀，其中宇宙达到最小尺度后反弹。 这种类型的正则时空是通过考虑某些标量场作为源，具有适当的动能项和标量势来实现的。 我们表明，由于动能项的符号错误，所有这些源最终都成为鬼场。 然而，可以通过约束消除这些鬼场。 尽管如此，同一过程也在修改引力的框架中进行了探索，特别是在所谓的f(R)引力中，得到了一种不需要鬼标量场的新虫洞时空。
Some novel regular spacetimes are considered that show a non-stationary wormhole structure. A Simpson-Visser-like procedure is applied to reconstruct these regular spacetimes, free of time-like and space-like singularities. Such a procedure is also applied to describe a regular cosmological expansion, where the universe reaches a minimum scale and then rebounds. This type of regular spacetime is achieved by considering some scalar fields as sources, with the appropriate kinetic term and scalar potential. We show that all these sources turn out to be ghosts due to the wrong sign of the kinetic term. These ghosts can, however, be eliminated by constraints. Nevertheless, the same procedure is also explored in the framework of modified gravities, particularly within the so-called f(R) gravity, where a new wormhole spacetime is also obtained that does not require a ghost scalar field.
- [14] arXiv:2508.05561 [中文pdf, pdf, html, 其他]
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标题： 在Reissner-Nordstrom背景下的味干涉测量标题： Flavour interferometry in Reissner-Nordstrom background评论： 8页，8图主题： 广义相对论与量子宇宙学 (gr-qc) ; 高能天体物理现象 (astro-ph.HE) ; 高能物理 - 现象学 (hep-ph)
我们推导中性标量粒子沿Reissner-Nordstrom测地线传播时获得的相位。 考虑两种不同轨迹上传播的风味，这些轨迹相交，我们绘制由带电致密天体引起的引力透镜效应引起的干涉图样。 尽管电荷在度规中是次主导因素，但它在相位中被证明是显著的，并且与Schwarzschild情况相比会改变干涉图样。 该图样由两个振荡长度特征化，如果已知这两个长度，将允许独立确定两种本征质量。
We derive the phase acquired by a neutral scalar particle propagating along Reissner-Nordstrom geodesics. Considering two flavours propagating on different trajectories which intersect, we plot the interference pattern induced by gravitational lensing from the charged compact object. Although the effect of the charge is subdominant in the metric, it proves to be significant in the phase, and shifts the interference pattern, compared to the Schwarzschild case. This pattern is characterised by two oscillation lengths which, if known, would allow the determination of both eigen masses independently.
新提交 (展示 14 之 14 条目 )
- [15] arXiv:2507.22974 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 四维中的热$n$-点共形块来自振子表示标题： Thermal $n$-Point Conformal Blocks in Four Dimensions from Oscillator Representations主题： 高能物理 - 理论 (hep-th)
我们通过在$\mathbb{S}^1_\beta \times \mathbb{S}^3$上使用振子表示，在投影通道中定义并计算四维热$n$点共形块。 这是通过在四维共形群的齐次空间$\mathbb{D}_4$上评估一类积分来完成的。 我们仅限于标量外部算符和标量交换。 在低温极限下，我们的结果正确地简化为梳状通道中的真空$(n+2)$点块。 相应的表达式可以写成终止超几何函数的级数，或者等价地，写成加权 SU(2) 自旋网络的级数。 另外，引入了适用于 SU(2,2) 表示的函数，并讨论了一些性质。
We define and compute the four-dimensional thermal $n$-point conformal block in the projection channel using oscillator representations on $\mathbb{S}^1_\beta \times \mathbb{S}^3$. This is done by evaluating a class of integrals over the homogeneous space $\mathbb{D}_4$ of the four-dimensional conformal group. We restrict ourselves to scalar external operators and scalar exchange. In the low-temperature limit, our result reduces correctly to the vacuum $(n+2)$-point block in the comb channel. The corresponding expressions can be written as a series of terminating hypergeometric functions or equivalently, a series of weighted SU(2) spin-networks. Alternatively, functions adapted to the SU(2,2) representation are introduced and some properties are discussed.
- [16] arXiv:2508.04771 (交叉列表自 astro-ph.HE) [中文pdf, pdf, html, 其他]
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标题： 力-free 黑洞磁层中阿尔芬波超辐射和布兰德福德-扎纳杰克过程的统一理解标题： Unified understanding of Alfvénic superradiance and the Blandford-Znajek process in a force-free black hole magnetosphere评论： 7页，3图主题： 高能天体物理现象 (astro-ph.HE) ; 广义相对论与量子宇宙学 (gr-qc)
我们研究通过阿尔芬波（即阿尔芬型超辐射）从克尔黑洞中提取能量，在这种无力磁层中忽略了等离子体惯性效应。 我们分析了向事件视界传播并穿过内光速面的阿尔芬波产生的波印廷通量，这是波的因果边界。 我们发现了与阿尔芬波相关的能量通量与布兰福德-扎纳杰克（BZ）过程的能量通量之间的关系。 也就是说，这两种机制都可以在波印廷通量的统一公式中描述，其中BZ过程可以被视为阿尔芬型超辐射的长波长极限，并且根据波的频率，阿尔芬波会增强或抑制BZ过程中的波印廷通量。 对于BZ过程和阿尔芬型超辐射的这一统一框架，将为理解高能天体物理现象（如相对论喷流）的能量来源提供有价值的视角。
We investigate the extraction of energy from a Kerr black hole via Alfv\'en waves (i.e., Alfv\'enic superradiance) in a force-free magnetosphere, in which the plasma inertia effects are ignored. We analyze the Poynting flux generated by Alfv\'en waves that propagate toward the event horizon across the inner light surface, the causal boundary for the waves. We find the relationship between the energy flux associated with Alfv\'en waves and that of the Blandford-Znajek (BZ) process. That is, both mechanisms can be described within a unified formulation of the Poynting flux, where the BZ process can be regarded as the long wavelength limit of the Alfv\'enic superradiance, and depending on the wave's frequency, Alfv\'en waves enhance or suppress the Poynting flux in the BZ process. This unified framework for the BZ process and the Alfv\'enic superradiance would offer a valuable perspective for understanding the energy sources of high-energy astrophysical phenomena, such as relativistic jets.
- [17] arXiv:2508.04877 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 标量和旋量场在引力宇宙弦时空中的情况标题： Scalar and spinor fields in gravitating cosmic string spacetimes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) ; 量子物理 (quant-ph)
我们研究标量场和旋量场在引力宇宙弦时空背景下的散射行为。 此处探讨的背景涡旋模型是非阿贝尔的，在适当的极限情况下变为阿贝尔的。 我们采用了我们在\cite{silva2021scattering}中开发的形式化方法，并对标准部分波方法进行了修改。 我们使用该方法研究标量场以及与具有非平凡渐近结构的背景时空相互作用的费米子场。 数值获得的时空度规，见\cite{de2015gravitating}，构成了我们最先进的数值研究的基础。 我们进行了详尽的分析，并将非阿贝尔模型中的所有结果与相应的阿贝尔模型进行比较，适用于无质量场和有质量场。 我们分析了场配置在核心附近小距离和大距离处的总截面和角度分布。 我们表明，总截面随着入射波的动量振荡，正如在\cite{silva2021scattering}中所预期的那样，并且角度分布可以用弗劳恩霍夫衍射图样合理地解释，特别是对于标量场的散射。
We study the scattering behavior of scalar and spinor fields in the background of a gravitating cosmic string spacetime. The model explored here for the background vortex is non-abelian, becoming abelian in an appropriate limiting case. We adopted the formalism we developed in \cite{silva2021scattering}, modifying the standard partial wave approach. We apply the method for a scalar and also a fermion field interacting with the background spacetime with a nontrivial asymptotic structure. The spacetime metric, obtained numerically in \cite{de2015gravitating}, forms the basis of our state-of-the-art numerical study. We make an exhaustive analysis and compare all the results in the non-abelian model with the corresponding abelian one for both massless and massive fields. We analyze the field configuration's total cross-section and angular profile at small and large distances from the core. We show that the total cross-section oscillates with the incident momentum of the wave, as anticipated in \cite{silva2021scattering}, and also, the angular profile can be explained reasonably well with a Fraunhofer diffraction pattern, especially for the scalar field scattering.
- [18] arXiv:2508.05117 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 共形Killing-Yano形式在具有反对称扭率的几何结构中的代数结构标题： Algebra structure of conformal Killing-Yano forms in geometries with skew-symmetric torsion评论： 12页主题： 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)
我们考虑与存在斜对称扭转时高阶形式的共形Killing向量的反对称推广相对应的共形Killing-Yano形式。 找到了带有扭转的共形Killing-Yano形式的可积性条件，并提出了一个分次李括号，使得共形 Killing-Yano 形式构成一个分次李代数结构。 发现对于常曲率和爱因斯坦流形上的闭合且平行的斜对称扭转，可以为带有扭转的共形 Killing-Yano 形式的特殊子集构建一个分次李代数结构。 还构建了从广义几何中的广义连接定义的广义隐藏对称性的类似结构。
We consider conformal Killing-Yano forms corresponding to the antisymmetric generalizations of conformal Killing vectors to higher degree forms in the presence of skew-symmetric torsion. Integrability conditions for torsionful conformal Killing-Yano forms are found and a graded Lie bracket for conformal Killing-Yano forms to constitute a graded Lie algebra structure is proposed. It is found that a graded Lie algebra structure for a special subset of torsionful conformal Killing-Yano forms can be constructed for a closed and parallel skew-symmetric torsion on constant curvature and Einstein manifolds. Similar structure for generalized hidden symmetries defined from generalized connection in generalized geometry is also constructed.
- [19] arXiv:2508.05158 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 因果相连子区域的纠缠度量和全息理论标题： Entanglement measures for causally connected subregions and holography评论： 67页，许多图表主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc) ; 量子物理 (quant-ph)
在本文中，我们研究量子场论和全息理论中因果关联子区域$A$和$B$的纠缠。最近的发展表明，对于这样的子区域可以很好地定义一个过渡算子$T_{AB}$，这通常是非厄米特的。通过采用 Schwinger-Keldysh 形式和实时复制方法，我们展示了如何构造$T_{AB}$并计算相关的纠缠度量。在某些配置中，这导致了一个类时纠缠熵的概念，我们提供了显式的量子场论计算，并通过从欧几里得设置的解析延拓提出了全息对偶。分析和数值结果进行了比较，发现是一致的。如果因果关联子区域之间的纠缠是有意义的，也应该能够定义其他纠缠度量。受类空情况的启发，我们提出了纠缠楔交叉部分的类时扩展，尽管我们不期望它具有相同的物理解释。在 AdS$_3$/CFT$_2$中，我们计算了显式例子并发现类时纠缠楔交叉部分通常是正的。此外，我们证明了类时区间的反射熵——通过扭曲相关函数的解析延拓得到的——在 $G$的主导阶下与两倍的类时纠缠楔交叉部分一致，支持了类时情况下的全息对偶性。我们还讨论了使用复制方法将其他纠缠度量（如对数否定）扩展到类时分离区域。我们强调了通过非厄米特算子的规范纯化来定义反射熵的概念性挑战。
In this paper, we investigate entanglement for causally connected subregions $A$ and $B$ in quantum field theory and holography. Recent developments have established that a transition operator $T_{AB}$ can be well-defined for such subregions, which is generally non-Hermitian. By employing the Schwinger-Keldysh formalism and the real-time replica method, we show how to construct $T_{AB}$ and compute associated entanglement measures. In certain configurations, this leads to a notion of timelike entanglement entropy, for which we provide explicit quantum field theory computations and propose a holographic dual via analytic continuation from the Euclidean setup. Both analytical and numerical results are compared and found consistent. If entanglement between causally connected subregions is to be meaningful, it should also be able to define other entanglement measures. Motivated by the spacelike case, we propose a timelike extension of the entanglement wedge cross section, though we do not expect it to carry the same physical interpretation. In AdS$_3$/CFT$_2$, we compute explicit examples and find that the timelike entanglement wedge cross section is generally positive. Furthermore, we show that the reflected entropy for timelike intervals -- obtained via analytic continuation of twist correlators -- coincides with twice the timelike entanglement wedge cross section at leading order in $G$, supporting a holographic duality in the timelike case. We also discuss the extension of other entanglement measures, such as logarithmic negativity, to timelike separated regions using replica methods. We highlight conceptual challenges in defining reflected entropy via canonical purification for non-Hermitian operators.
- [20] arXiv:2508.05322 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 非极端Kerr AdS$_4$黑洞的熵和霍金辐射中的普遍性探索标题： Explorations of Universality in the Entropy and Hawking Radiation of Non-Extremal Kerr AdS$_4$ Black Holes评论： 33页，4图主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
我们全面讨论了在规范超引力中旋转、带电、渐近AdS$_4$非极端黑洞的Bekenstein-Hawking熵的各种微观方法。我们应用协变相空间形式到近视界区域，以获得基于Cardy公式的小规模解释，与Kerr/CFT对应一致。从对偶边界CFT的观点来看，我们在高温区域中使用矩阵模型近似估计自由配分函数，并发现与超引力答案有定性一致的结果。所有这些不同的方法在适当极限下匹配，并支持AdS黑洞熵的普遍性，即使在远离极端性的高温情况下。鉴于统计解释对于AdS$_4$黑洞熵结果的一致性，我们从CFT$_2$的角度讨论了高温下的霍金辐射速率，并发现其与视界面积成普遍比例。
We comprehensively discuss various microscopic approaches to the Bekenstein-Hawking entropy for rotating, electrically charged, asymptotically AdS$_4$ non-extremal black holes in gauged supergravity. We apply the covariant phase space formalism to the near-horizon region to obtain a Cardy-formula-based microscopic explanation for the entropy, consistent with the Kerr/CFT correspondence. From the dual boundary CFT point of view, we estimate the free partition function in the matrix model approximation in the high-temperature regime and find qualitative agreement with the supergravity answer. All these different approaches match in the appropriate limits and support the universality of AdS black hole entropy even at high temperatures, far away from extremality. Prompted by the consistency of the results of statistical explanations for the AdS$_4$ black hole entropy, we discuss aspects of the rate of Hawking radiation at high temperatures from the CFT$_2$ perspective and found it to be universally proportional to the horizon area.
- [21] arXiv:2508.05384 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 通过思想实验在AdS$_3$中违反弱宇宙审查猜想标题： Violating Weak Cosmic Censorship in AdS$_3$ via Gedanken Experiment评论： 6页，4图主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
弱宇宙审查猜想（wCCC）可能不像人们预期的那样稳固。 我们提出了一种可能的反例，针对旋转的三维反德西特（AdS$_3$）时空中的wCCC。 我们扩展了量子修正BTZ（qBTZ）黑洞的参数范围。 我们研究了具有大轨道角动量的测试粒子落入极端黑洞的情况。 我们的研究结果表明，在某些条件下——例如忽略自力效应——事件视界可能会被破坏，从而导致wCCC的违反。 这些结果表明，该解要么应被排除在wCCC的应用范围之外，要么应在考虑自力效应的情况下进行进一步研究。
The weak cosmic censorship conjecture (wCCC) might not be as robust as one would expect. We present a potential counterexample to the wCCC in a rotating three-dimensional anti-de Sitter (AdS$_3$) spacetime. We extend the parameter range of the quantum corrected BTZ (qBTZ) black hole. We examine the infall of test particles with large orbital angular momentum into an extremal black hole. Our findings indicate that, under certain conditions -- such as neglecting the self-force effects -- the event horizon can be destroyed, leading to a violation of the wCCC. The results suggest that this solution should either be excluded from the applicability of the wCCC or should be examined with self-force effects incorporated.
- [22] arXiv:2508.05395 (交叉列表自 astro-ph.CO) [中文pdf, pdf, html, 其他]
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标题： 宇宙弦在LISA的引力波背景：I. 信号调查，模板重建和模型比较标题： Cosmic string gravitational wave backgrounds at LISA: I. Signal survey, template reconstruction, and model comparison评论： 64页 + 35图（附录：10页 + 4图），引力波模板仓库链接：https://github.com/peerasima/cosmic-strings-GWB，GWBackFinder链接：https://github.com/AndronikiDimitriou/GWBackFinder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)
我们提供了一个基于文献中相关模型的宇宙弦网络引力波背景（GWB）信号模板目录。 我们将模板分为传统类型，基于标准宇宙学和Nambu-Goto结果（VOS和BOS），以及超出传统的类型，基于a) 环数量密度的修改（LRS、超、亚稳态、携带电流的弦），b) 膨胀历史的修改（非标准宇宙学、额外自由度，无论是热的还是隔离的），或c) 环属性的修改（产生长度、功率发射）。 使用SBI软件包 $\texttt{GWBackFinder}$，我们通过扫描其参数空间并进行模型比较，量化了LISA对每个信号的重建精度。 对于传统信号，LISA能够以误差 $G\mu$重建张力 $\lesssim 10\%$ ，对于 $G\mu \gtrsim 5\cdot 10^{-15}$ ，该误差下降至 $2-3\%$ 对于 $G\mu \gtrsim 10^{-12}$。 BOS和VOS模型在 $G\mu \gtrsim 5\cdot 10^{-13}$ 时可以被可靠地区分。 对于超出传统类型的信号，我们确定了每个参数的信噪比和误差阈值区间，并确定（对于少数例子）它们可以与传统信号区分开来的区域。 关于叠加在LISA窗口中主要天体物理前景上的宇宙弦GWB的类似质量重建研究，将在一系列即将发表的论文中呈现。
We present a catalog of gravitational wave background (GWB) signal templates from cosmic-string networks, based on relevant models proposed in the literature. We classify templates as conventional, based on standard cosmology and Nambu-Goto results (VOS and BOS), and beyond conventional, based on modifications of a) the loop number density (LRS, super, metastable, current-carrying strings), b) the expansion history (non-standard cosmologies, extra degrees of freedom, either thermal or secluded), or c) the loop properties (birth length, power emission). Using the SBI package $\texttt{GWBackFinder}$, we quantify the reconstruction precision of each signal by LISA, scanning over their parameter space, and performing model comparisons. For conventional signals, LISA reconstructs the tension $G\mu$ with an error $\lesssim 10\%$ for $G\mu \gtrsim 5\cdot 10^{-15}$, which decreases down to $2-3\%$ for $G\mu \gtrsim 10^{-12}$. BOS and VOS modelings become distinguishable confidently for $G\mu \gtrsim 5\cdot 10^{-13}$. For beyond-conventional signals, we identify SNR and error-threshold intervals for each parameter, and determine (for few examples) the regions where they can be distinguished from conventional signals. Analogous quality reconstruction studies of cosmic-string GWBs, superimposed over leading astrophysical foregrounds in the LISA window, will be presented in a series of upcoming papers.
- [23] arXiv:2508.05436 (交叉列表自 astro-ph.CO) [中文pdf, pdf, html, 其他]
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标题： DBI暗能量与变色龙机制的约束标题： Constraints on DBI dark energy with chameleon mechanism评论： 10页 8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)
在本工作中，我们根据最新的宇宙学观测研究了狄拉克布罗恩-因菲尔德标量场模型，分析该模型时既考虑了卡门机制，也未考虑它。 当前宇宙学观测的结果，如Pantheon Plus、DES Y5、DESI DR2和压缩的普朗克似然函数，被用来约束该模型。 我们考虑了AdS喉部的形式为$f(\phi) = \lambda / \phi^4$和势能$V(\phi) = m_0^2 \phi^2 + m_1^2 \phi^4$。我们分析的一个有趣发现是，不考虑卡门机制时，$m_1 \simeq 0$的均值表明DBI场的自相互作用可能可以忽略。 在考虑卡门机制时，势能参数的约束不存在，但扭曲参数和卡门耦合参数必须满足$\eta \geq 0$和$\beta \leq 0$。 不同选择的$\beta$导致相同的背景宇宙学参数。 状态方程$w_{\rm DE}$在过去更多位于 quintessence 区域。 在我们对扭曲喉部和势能的假设下，该模型中没有出现phantom穿越。 通过计算相对于$\Lambda$CDM 模型的$\Delta \text{AIC}$，我们研究统计模型比较。 该模型作为动力学暗能量的候选者，在宇宙学背景层面上是观测可行的。
In this work, we investigate the Dirac Born Infeld chameleon scalar field model in light of the latest cosmological observations, analyzing the model both with the incorporation of the chameleon mechanism and without it. Results from current cosmological observations, such as Pantheon Plus, DES Y5, DESI DR2, and the compressed Planck likelihood, are used to constrain the model. We consider the AdS throat in the form of $f(\phi) = \lambda / \phi^4$ and a potential $V(\phi) = m_0^2 \phi^2 + m_1^2 \phi^4$ .One interesting finding from our analysis is that, without the chameleon mechanism, the mean value of $m_1 \simeq 0$ indicates the self-interaction of the DBI field could potentially be negligible. Constraints on the potential parameters do not appear when considering the chameleon mechanism, but the warp parameter and chameleon coupling parameter are forced to satisfy $\eta \geq 0$ and $\beta \leq 0$. Different choices of $\beta$ render the same background cosmological parameters. The equation of state $w_{\rm DE}$ resides more in the quintessence region in the past. There is no phantom crossing in this model under our assumption of the warp throat and potential. By computing the $\Delta \text{AIC}$ relative to the $\Lambda$CDM model, we study statistical model comparison. The model as a candidate of dynamical dark energy is observationally viable at the cosmological background level.
交叉提交 (展示 9 之 9 条目 )
- [24] arXiv:2502.08199 (替换) [中文pdf, pdf, html, 其他]
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标题： 在量子多体系统中模拟霍金辐射：与热谱的偏差标题： Simulating Hawking radiation in quantum many-body systems: deviations from the thermal spectrum评论： 发表于PLB的版本主题： 广义相对论与量子宇宙学 (gr-qc) ; 量子物理 (quant-ph)
我们研究了一种最近提出的二维弯曲时空中的量子场论与量子多体系统之间的一一对应关系，这使得在静态背景时空下模拟霍金辐射成为可能。 特别是，我们证明了根据著名的隧穿方法预测的热谱偏差可以在多体模拟中观察到。
We investigate a recently proposed one-to-one correspondence between quantum field theories in two-dimensional curved spacetime and quantum many-body systems, which enables the simulation of Hawking radiation in static background spacetimes. In particular, we demonstrate that deviations from the thermal spectrum, as predicted by the well-known tunneling method, can be observed in many-body simulations.
- [25] arXiv:2503.10998 (替换) [中文pdf, pdf, html, 其他]
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标题： 蜂鸟引力：远离势能极小值的球对称解标题： Bumblebee gravity: spherically-symmetric solutions away from the potential minimum评论： 26页双栏格式，11图，5表，v2：对图表、文本讨论进行澄清和修改，修正了拼写错误，与已发表版本一致期刊参考： 物理评论D 112，024069 (2025)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，我们研究了一个与引力耦合的自发时空对称性破缺的矢量模型：bumblebee 模型。 主要关注静态球对称解。 补充之前关于黑洞解的工作，我们研究当矢量场不在其势能最小值时对解的影响。 我们首先研究平直时空极限，这可以看作是一种具有非线性相互作用项的修改后的静电模型。 我们一般性地研究了经典解的稳定性以及球对称情况下的稳定性。 我们还发现，某些基于超几何函数的势能，会产生下有界的哈密顿量。 在引入引力的情况下，我们求解了球对称度规和矢量场，对于各种势能函数的选择，包括超出二次势能的超几何势能。 得到了一些特殊情况的精确解，展示了 Schwarszchild-Anti de Sitter 和 Reissner-Nordstrom 时空。 我们采用视界和渐近解析展开以及数值解来探索矢量场远离势能最小值的一般情况。 我们发现了这些解的一些有趣特性，包括裸奇点、排斥性引力以及靠近源处快速变化的引力场。 最后，我们使用所得的轨道行为讨论了这些时空的观测约束。
In this work, we study a vector model of spontaneous spacetime-symmetry breaking coupled to gravity: the bumblebee model. The primary focus is on static spherically symmetric solutions. Complementing previous work on black hole solutions, we study the effects on the solutions when the vector field does not lie at the minimum of its potential. We first investigate the flat spacetime limit, which can be viewed as a modified electrostatic model with a nonlinear interaction term. We study the stability of classical solutions generally and in the spherically-symmetric case. We also find that certain potentials, based on hypergeometric functions, yield a Hamiltonian bounded from below. With gravity, we solve for the spherically-symmetric metric and vector field, for a variety of choices of the potential energy functions, including ones beyond the quadratic potential like the hypergeometric potentials. Special case exact solutions are obtained showing Schwarszchild-Anti de Sitter and Reissner-Nordstrom spacetimes. We employ horizon and asymptotic analytical expansions along with numerical solutions to explore the general case with the vector field away from the potential minimum. We discover interesting features of these solutions including naked singularities, repulsive gravity, and rapidly varying gravitational field near the source. Finally, we discuss observational constraints on these spacetimes using the resulting orbital behavior.
- [26] arXiv:2504.04331 (替换) [中文pdf, pdf, html, 其他]
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标题： 揭示引力：洛伦兹规范理论中的黑洞阴影和透镜效应特征标题： Shedding Light on Gravity: Black Hole Shadows and Lensing Signatures in Lorentz Gauge Theory评论： 22页，7图，即将发表于《核物理B》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) ; 高能物理 - 理论 (hep-th) ; 数学物理 (math-ph)
Recent advances, including gravitational wave detections and imaging of black hole shadows, have strongly validated general relativity. Nevertheless, ongoing cosmological observations suggest potential limitations of general relativity, spurring interest in modified theories of gravity. This work investigates the Lorentz-gauge formulation of gravity-a novel framework that addresses key conceptual challenges in quantum gravity and cosmology by leveraging the recent black hole solutions presented in Ref. \cite{Koivisto:2024asr}. By analyzing black hole shadow structures and gravitational lensing effects-both weak and strong deflection regimes-we highlight unique observational signatures of Lorentz gauge gravity. Our findings provide valuable tools for future observational tests, potentially distinguishing these modified gravity models from general relativity and advancing our understanding of spacetime geometry and fundamental gravitational interactions.
Recent advances, including gravitational wave detections and imaging of black hole shadows, have strongly validated general relativity. Nevertheless, ongoing cosmological observations suggest potential limitations of general relativity, spurring interest in modified theories of gravity. This work investigates the Lorentz-gauge formulation of gravity-a novel framework that addresses key conceptual challenges in quantum gravity and cosmology by leveraging the recent black hole solutions presented in Ref. \cite{Koivisto:2024asr}. By analyzing black hole shadow structures and gravitational lensing effects-both weak and strong deflection regimes-we highlight unique observational signatures of Lorentz gauge gravity. Our findings provide valuable tools for future observational tests, potentially distinguishing these modified gravity models from general relativity and advancing our understanding of spacetime geometry and fundamental gravitational interactions.
- [27] arXiv:2504.14537 (替换) [中文pdf, pdf, html, 其他]
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标题： 哥德尔的宇宙与非局部引力的局部极限标题： Gödel's Universe and the Local Limit of Nonlocal Gravity评论： 18页；v2：演示文稿得到改进，发表于《物理年鉴》在线版主题： 广义相对论与量子宇宙学 (gr-qc)
我们考虑在非局部引力的局部极限背景下戈德尔宇宙。 该理论通过存在一个标量感应函数$S(x)$而不同于爱因斯坦的广义相对论（GR），该函数是引力场的特征，并在GR极限中消失。 我们证明，当$S$为常数时，戈德尔时空是修改后的引力场方程的解，这与戈德尔宇宙的空间均匀性一致。
We consider the G\"odel universe within the context of the local limit of nonlocal gravity. This theory differs from Einstein's general relativity (GR) through the existence of a scalar susceptibility function $S(x)$ that is a characteristic feature of the gravitational field and vanishes in the GR limit. We show that G\"odel's spacetime is a solution of the modified gravitational field equations provided $S$ is a constant, in conformity with the spatial homogeneity of the G\"odel universe.
- [28] arXiv:2506.17856 (替换) [中文pdf, pdf, html, 其他]
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标题： 四功能广义和带源的Plebanski时空的可分离结构标题： Four-function generalization and separable structures of the Plebanski spacetime with sources评论： 21页；一张表格；2个附录主题： 广义相对论与量子宇宙学 (gr-qc)
我们确定了Plebanski时空的四函数推广，该时空依赖于径向坐标的三个任意函数和角坐标的一个函数。 对于广义的Plebanski时空，我们分析了哈密顿-雅可比方程的可分离性，带电测试粒子的轨迹是从运动常数中导出的。 建立了克莱因-戈登方程的可分离性，并给出了Killing视界。 然后我们向Plebanski度规引入了一个共形因子，并讨论了保持可分离性的条件。 最后我们展示了一个可能的应力-能量张量，这可能是某些广义度规的来源。
We determine a four-function generalization of the Plebanski spacetime, depending on three arbitrary functions of the radial coordinate, and one function on the angular coordinate. For the generalized Plebanski spacetime, we analyze the separability of the Hamilton--Jacobi equations, and the trajectories of charged test particles are derived from the motion constants. The Klein-Gordon equation separability is established and the Killing horizons are presented as well. Then we introduce a conformal factor to the Plebanski metric and discuss the conditions that preserve the separability. Finally we show a possible stress--energy tensor that may be the source of some of the generalized metrics.
- [29] arXiv:2507.21808 (替换) [中文pdf, pdf, 其他]
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标题： 外部引力场中的量子干涉仪标题： Quantum interferometry in external gravitational fields评论： 18页，7图主题： 广义相对论与量子宇宙学 (gr-qc) ; 量子物理 (quant-ph)
当前在外部引力场中的量子干涉实验模型缺乏一个共同框架：虽然物质波干涉仪通常使用包含牛顿势的薛定谔方程来描述，但量子光学中的引力效应则使用后牛顿度规或爱因斯坦场方程的高度对称精确解，如施瓦茨希尔德和克尔解来建模。 为了一致地描述这两种实验，本文开发了一个统一的框架，用于在一般静态时空中的量子干涉仪建模。 该模型提供了对经典引力对量子探测器影响的严格描述和一致解释。
Current models of quantum interference experiments in external gravitational fields lack a common framework: while matter-wave interferometers are commonly described using the Schr\"odinger equation with a Newtonian potential, gravitational effects in quantum optics are modeled using either post-Newtonian metrics or highly symmetric exact solutions to Einstein's field equations such as those of Schwarzschild and Kerr. To coherently describe both kinds of experiments, this paper develops a unified framework for modeling quantum interferometers in general stationary space-times. This model provides a rigorous description and coherent interpretation of the effects of classical gravity on quantum probes.
- [30] arXiv:2508.02768 (替换) [中文pdf, pdf, html, 其他]
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标题： 基于李雅普诺夫指数的施瓦茨希尔德AdS黑洞周围弦云相结构分析标题： Lyapunov Exponent Approach to Phase Structure of Schwarzschild AdS Black Holes Surrounded by a Cloud of Strings评论： 添加了文本和参考文献主题： 广义相对论与量子宇宙学 (gr-qc)
我们研究了被弦云包围的反德西特（AdS）时空中的施瓦茨希尔德黑洞（BH-AdS-CoS），结合了弦双矢量的电和磁类似分量。 热力学上，这些系统表现出小/中/大黑洞相，一阶和二阶转变由弦参数$c_0$控制。 动力学上，我们通过不稳定圆测地线的李雅普诺夫指数$\lambda$来探测相结构。 对于无质量粒子（$\delta = 0$），解析表达式$\lambda$在一阶转变区域（$c_0 < c_{\text{cri}}$）显示出多值行为，分支映射到热力学相（$\lambda_{\text{SBH}}, \lambda_{\text{IBH}}, \lambda_{\text{LBH}}$）。 不连续性$\Delta\lambda = \lambda_{\text{SBH}} - \lambda_{\text{LBH}}$在$T_p$上遵循均场标度：$\Delta\lambda / \lambda_{\text{cri}} \propto (T_\text{cri} - T)^{1/2} \quad (\beta = 1/2)$。对于大质量粒子（$\delta = 1$），类时测地线的数值计算确认$\lambda$作为序参量，临界指数$\beta = 1/2$具有普遍性。 关键区别显现出来：对于光子，$\lambda\to 1$渐近成立，而由于不稳定轨道的消失，在大质量粒子的重要黑洞相中，$\lambda\to 0$成立。 $\lambda$从多值到单值的转变在$c_0 = c_{\text{cri}}$处确立了它作为黑洞临界性的通用动力学探针。 \(\Delta\lambda\)的普遍临界指数 1/2 进一步加强了与常规热力学系统的类比。 我们的结果证实了 BH-AdS-CoS 热力学相结构与测试粒子动力学之间的直接联系，其中李雅普诺夫指数作为黑洞临界性的敏感诊断工具浮现出来。
We investigate Schwarzschild black holes in anti-de Sitter (AdS) spacetimes surrounded by a cloud of strings (BH-AdS-CoS), incorporating both electric- and magnetic-like components of the string bi-vector. Thermodynamically, these systems exhibit small/intermediate/large black hole phases with first- and second-order transitions governed by the string parameter $c_0$. Dynamically, we probe the phase structure using Lyapunov exponents $\lambda$ from unstable circular geodesics. For massless particles ($\delta = 0$), analytical expressions $\lambda$ reveal multivalued behavior in first-order transition regimes ($c_0 < c_{\text{cri}}$), with branches mapping to thermodynamic phases ($\lambda_{\text{SBH}}, \lambda_{\text{IBH}}, \lambda_{\text{LBH}}$). The discontinuity $\Delta\lambda = \lambda_{\text{SBH}} - \lambda_{\text{LBH}}$ at $T_p$ follows mean-field scaling: $\Delta\lambda / \lambda_{\text{cri}} \propto (T_\text{cri} - T)^{1/2} \quad (\beta = 1/2)$. For massive particles ($\delta = 1$), numerical computation of timelike geodesics confirms $\lambda$ as an order parameter, with critical exponent $\beta = 1/2$ universally. Key distinctions emerge: $\lambda\to 1$ asymptotically for photons, while $\lambda\to 0$ in the significant black hole phase for massive particles due to vanishing unstable orbits. The transition of $\lambda$ from multivalued to single-valued at $c_0 = c_{\text{cri}}$ establishes it as a universal dynamical probe of black hole criticality. The universal critical exponent of 1/2 for \(\Delta\lambda\) further reinforces the analogy with conventional thermodynamic systems. Our results confirm a direct connection between the thermodynamic phase structure of BH-AdS-CoS and the dynamics of test particles, with the Lyapunov exponent emerging as a sensitive diagnostic of black hole criticality.
- [31] arXiv:2508.03602 (替换) [中文pdf, pdf, html, 其他]
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标题： 用DESI BAO数据测试高斯-博内引力标题： Testing Gauss-Bonnet Gravity with DESI BAO DataPraveen Kumar Dhankar, Dalale Mhamdi, Albert Munyeshyaka, Darshan Kumar, Joseph Ntahompagaze, Taoufik Ouali评论： 21页，6图主题： 广义相对论与量子宇宙学 (gr-qc)
在本文中，我们通过使用Pantheon Plus（PP）样本中的Ia型超新星、宇宙时钟（CC）数据以及DESI发布的最新重子声学振荡（BAO）测量数据，在背景层面上对f（G）引力进行观测约束。 对于分析，我们考虑了两种数据集组合：（i）PP + CC，以及（ii）PP + CC + DESI BAO。 在两种情况下，我们通过数值求解两种不同的f（G）模型的修改后的弗里德曼方程来确定最佳拟合参数，即幂律形式和指数形式。 这是通过马尔可夫链蒙特卡洛（MCMC）模拟实现的。 为了评估f（G）模型的统计显著性，我们同时采用了 赤池信息准则（AIC）和贝叶斯信息准则 （BIC）。 我们的结果表明，这两种f（G）模型在统计上优于标准 {\Lambda }CDM 模型。 值得注意的是，指数模型在红移更接近-0.1处表现出额外的未来转变，表明可能返回到减速阶段。 这种独特的行为使其区别于幂律模型和 {\Lambda }CDM 场景，后者预测未来将持续加速。
In the present paper, we observationally constrain f (G) gravity at the background level using Type Ia supernovae from the Pantheon Plus (PP) sample, cosmic chronometer (CC) data, and the recent Baryon Acoustic Oscillation (BAO) measurements released by DESI. For the analysis, we consider two combinations of datasets: (i) PP + CC, and (ii) PP + CC + DESI BAO. In both cases, we determine the best-fit parameters by numerically solving the modified Friedmann equations for two distinct f (G) models, namely the power-law and exponential forms. This is achieved through Markov Chain Monte Carlo (MCMC) simulations. To assess the statistical significance of the f (G) models, we employ both the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Our results show that both f (G) models are statistically favored over the standard {\Lambda}CDM model. Notably, the exponential model exhibits an additional future transition at redshift closer to -0.1, indicating a possible return to a decelerating phase. This distinctive behavior sets it apart from both the power-law model and the {\Lambda}CDM scenario, which predict continued acceleration into the future.
- [32] arXiv:2504.09054 (替换) [中文pdf, pdf, html, 其他]
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标题： 利用晚期宇宙观测比较暗能量模型标题： Comparison of dark energy models using late-universe observations评论： 23页，13图。已接受发表于《物理评论D》。这是接受稿。最终发表版本将可在 [...] 获取。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)
在广义相对论的框架下，暗能量被提出以解释宇宙加速膨胀。 宇宙学中的一个关键问题是确定暗能量是否是宇宙学常数，如果不是，挑战在于限制它随时间演化的方式。 在本文中，我们利用最新的观测数据来约束一些典型的暗能量模型，并根据它们拟合当前数据的能力进行比较。 我们的研究仅限于晚期宇宙观测，包括重子声学振荡、Ia型超新星、宇宙时钟和强引力透镜时间延迟数据。 我们使用Akaike信息准则（AIC）、偏差信息准则（DIC）和贝叶斯信息准则（BIC）来评估模型的价值。 AIC和DIC分析表明，所有暗能量模型都优于$\Lambda$CDM 模型。 然而，由于对模型复杂性的惩罚更重，BIC分析为$\Lambda$CDM 留下了空间。 与$\Lambda$CDM 相比，大多数暗能量模型在AIC和DIC下得到稳健支持，而在BIC下被明确排斥。 在AIC和DIC下得到稳健支持且未被BIC明确排斥的模型包括$w$CDM、相互作用暗能量和里奇暗能量模型。 此外，我们观察到，与$\Lambda$CDM 相比，一种替代的修改引力模型在所有信息准则下表现出更优的性能。
In the framework of general relativity, dark energy was proposed to explain the cosmic acceleration. A pivotal inquiry in cosmology is to determine whether dark energy is the cosmological constant, and if not, the challenge lies in constraining how it evolves with time. In this paper, we utilize the latest observational data to constrain some typical dark energy models, and make a comparison for them according to their capabilities of fitting the current data. Our study is confined to late-universe observations, including the baryon acoustic oscillation, type Ia supernova, cosmic chronometer, and strong gravitational lensing time delay data. We employ the Akaike information criterion (AIC), deviance information criterion (DIC), and Bayesian information criterion (BIC) to assess the worth of models. The AIC and DIC analyses indicate that all dark energy models outperform the $\Lambda$CDM model. However, the BIC analysis leaves room for $\Lambda$CDM due to its heavier penalty on the model complexity. Compared to $\Lambda$CDM, most dark energy models are robustly supported by AIC and DIC while being explicitly disfavored by BIC. The models that are robustly favored by AIC and DIC and not explicitly disfavored by BIC include the $w$CDM, interacting dark energy, and Ricci dark energy models. Furthermore, we observe that an alternative modified gravity model exhibits superior performance when compared with $\Lambda$CDM across all information criteria.
- [33] arXiv:2504.12282 (替换) [中文pdf, pdf, 其他]
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标题： 量子面积涨落来自引力相空间标题： Quantum Area Fluctuations from Gravitational Phase Space评论： 28页，1图；v2：小幅度修改，即将发表在JHEP上主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
我们研究在$(d+2)$维时空中的有限大小因果钻石相关的引力相空间。 通过施加 Raychaudhuri 方程，我们使用协变相空间形式获得了其约束辛形式，并通过反转辛形式并进行量子化推导出相关的量子对易子。 最后，我们通过纯闵可夫斯基时空中伸展视界的 Carroll 极限计算了因果钻石的面积涨落，并推导出关系$\langle (\Delta A)^2 \rangle \geq \frac{2\pi G}{d}\langle A \rangle$，表明面积涨落的方差与面积本身成正比。
We study the gravitational phase space associated to a stretched horizon within a finite-sized causal diamond in $(d+2)$-dimensional spacetimes. By imposing the Raychaudhuri equation, we obtain its constrained symplectic form using the covariant phase space formalism and derive the relevant quantum commutators by inverting the symplectic form and quantizing. Finally, we compute the area fluctuations of the causal diamond by taking a Carrollian limit of the stretched horizon in pure Minkowski spacetime, and derive the relationship $\langle (\Delta A)^2 \rangle \geq \frac{2\pi G}{d}\langle A \rangle$, showing that the variance of the area fluctuations is proportional to the area itself.
- [34] arXiv:2504.13738 (替换) [中文pdf, pdf, html, 其他]
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标题： 高能弦理论与全息球面标题： High Energy String Theory and the Celestial Sphere评论： 29页，LaTeX，2图；v2：第4节“关于无张力弦振幅的评论”得到改进和扩展；最终版本将发表在JHEP上主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
我们详细阐述了弦世界面与平直时空全息理论之间的联系。 更具体地说，在平直背景中树图弦散射的高能（零张力）极限下，底层的弦世界面可以与天体球面相关联，高能弦描述中的鞍点代表天体球面上的点。 我们证明，这种图像在该经典配置周围的量子涨落的所有次领头阶仍成立。 因此，弦理论的高能极限存在一种对偶描述，即作为天体球面上的大能量展开，由（轻）高自旋模态组织。 这种方法指向了通过将其与弦理论的（自由）世界面共形场论（CFT）相关联来内在构造天体共形场论（CFT）。 我们还详细阐述了树图开弦和闭弦振幅的高能表示，并推导出它们的次领头修正。 讨论了它们的数论性质及其作为无张力弦振幅的相关性。
We elaborate on a string world-sheet connection to flat space-time holography. More specifically, in the high energy (zero tension) limit of tree-level string scattering in flat backgrounds the underlying string world-sheets can be related to the celestial sphere, with the saddle points of the high energy string description representing points on the celestial sphere. We show that this picture continues to hold at all subleading orders in the quantum fluctuations around this classical configuration. As a consequence there is a dual description of the high energy limit of string theory as the large energy expansion on the celestial sphere organized by (light) higher spin modes. This approach points to an intrinsic construction of celestial conformal field theory (CFT) by relating it to a (free) world-sheet CFT of string theory. We also elaborate on the high energy representations of tree-level open and closed string amplitudes and work out their subleading corrections. Their number theoretic properties and relevance as amplitudes of tensionless strings are discussed.
- [35] arXiv:2505.05448 (替换) [中文pdf, pdf, html, 其他]
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标题： 旋转热态在反德西特时空中的量子效应标题： Quantum effects in rotating thermal states on anti-de Sitter space-time评论： 10页，6幅图，小修改，已接受发表于《物理快报B》主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
我们研究了在三维和四维反德西特时空中的刚性旋转热态下，无质量、共形耦合的量子标量场的能量-动量张量。 我们首先使用相对论动力学理论找到能量-动量张量，将场建模为无质量玻色子的热气体。 然后我们在量子场论中计算标量场的重整化后的能量-动量张量，并将其与相对论动力学理论的结果进行比较。
We study the stress-energy tensor of a massless, conformally coupled, quantum scalar field in a rigidly-rotating thermal state on three- and four-dimensional anti-de Sitter space-time. We first find the stress-energy tensor using relativistic kinetic theory, modelling the field as a thermal gas of massless bosons. We then compute the renormalized stress-energy tensor of the scalar field in quantum field theory and compare it with that resulting from relativistic kinetic theory.
- [36] arXiv:2505.16578 (替换) [中文pdf, pdf, html, 其他]
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标题： 标准运行，“物理运行”，宇宙学常数和牛顿耦合标题： Standard Running, "Physical Running", Cosmological Constant and Newton Coupling评论： 6页；增加了引言和参考文献，进行了小幅度修改主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
最近有主张认为，标准的beta函数不能正确描述某些理论中耦合常数的运行。 我们表明，问题源于假设$\mu=p$（$\mu$是一个重整化点），并且适当选择$\mu$可以得到正确的运行。 还声称，宇宙学常数和牛顿耦合都不运行。 我们认为，当我们考虑弯曲时空时，可以讨论运行。
Recently it is asserted that the standard beta function does not describe the correct running of the coupling constant in some theories. We show that the problem arises from the assumption $\mu=p$ ($\mu$ is a renormalization point) and that a suitable choice of $\mu$ gives the correct running. It is also claimed that neither the cosmological constant nor Newton coupling run. We argue that running can be discussed when we consider the curved spacetime.
- [37] arXiv:2507.22120 (替换) [中文pdf, pdf, html, 其他]
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标题： 任意负能量对于小卡鲁扎-克莱因泡标题： Arbitrarily Negative Energy for Small Kaluza-Klein Bubbles评论： 16页，4图。v2：更正了一些拼写错误主题： 高能物理 - 理论 (hep-th) ; 广义相对论与量子宇宙学 (gr-qc)
我们证明，即使在无限远处圆的大小和气泡处最小球面的大小固定的情况下，Kaluza-Klein 无物气泡的 ADM 能量也是无下限的。 我们通过提出一组满足这些边界条件的显式时间对称初始数据来证明这一点，这些数据具有任意负的能量。 特别是，这对于非常小的气泡来说是正确的，这表明标准的 Kaluza-Klein 真空比之前认为的更不稳定。
We show that the ADM energy of a Kaluza-Klein bubble of nothing is unbounded from below even if the size of the circle at infinity and the size of the minimal sphere at the bubble are fixed. We demonstrate this by presenting a family of explicit time-symmetric initial data satisfying these boundary conditions with arbitrarily negative energy. In particular, this is true for very small bubbles, which indicates that the standard Kaluza-Klein vacuum is more unstable than previously thought.