标题： N体模拟用于耦合标量场宇宙学 显示英文标题

标题： N-Body Simulations for Coupled Scalar Field Cosmology

摘要： 我们详细描述了耦合标量场宇宙学模型中一致的N体模拟的一般方法和数值实现，包括背景宇宙学和初始条件的生成（考虑了与不同物质种类的不同耦合）。 我们对具有反幂律势和负耦合常数的耦合标量场模型类进行了完全一致的模拟，对于这些模型，卡门机制不起作用。 我们发现，在这样的宇宙学模型中，标量场势除了在背景膨胀中起微不足道的作用外，其他情况下都无关紧要，所产生的第五种力的大小与引力成正比，这证明了在一些类似模型的早期N体模拟中使用重新缩放的引力常数G是合理的。 我们研究了标量耦合对非线性物质功率谱的影响，并与线性扰动计算进行比较，以探讨非线性模型在何处偏离线性近似。 首次将识别引力束缚物质晕的算法适应于标量场宇宙学，然后用于测量质量函数并研究束缚晕的特性。 我们发现，标量耦合的净效应有助于在我们的模拟箱中产生更多的大质量晕，并与lambda-CDM预测相比，抑制了晕的内部（但不是外部）密度剖面，而这种抑制随着标量场与暗物质粒子之间的耦合强度增加而减弱。 显示英文摘要

摘要： We describe in detail the general methodology and numerical implementation of consistent N-body simulations for coupled scalar field cosmological models, including the background cosmology and the generation of initial conditions (with the different couplings to different matter species taken into account). We perform fully consistent simulations for a class of coupled scalar field models with an inverse power-law potential and negative coupling constant, for which the chameleon mechanism does not operate. We find that in such cosmological models the scalar-field potential plays a negligible role except in the background expansion, and the fifth force that is produced is proportional to gravity in magnitude, justifying the use of a rescaled gravitational constant G in some earlier N-body simulations of similar models. We study the effects of the scalar coupling on the nonlinear matter power spectra and compare with linear perturbation calculations to investigate where the nonlinear model deviates from the linear approximation. For the first time, the algorithm to identify gravitationally virialized matter halos is adapted to the scalar field cosmology, and then used to measure the mass function and study the properties of virialized halos. We find that the net effect of the scalar coupling helps produce more heavy halos in our simulation boxes and suppresses the inner (but not the outer) density profile of halos compared with those predicted by lambda-CDM, while this suppression weakens as the coupling between the scalar field and dark matter particles increases in strength.