标题： 相对论性N体模拟中的弱透镜观测量 显示英文标题

标题： Weak-lensing observables in relativistic N-body simulations

摘要： 我们提出了一种数值弱透镜分析方法，该方法对于引力势的标量部分是完全相对论性的且非微扰的，对于矢量部分（包括框架拖拽）是一阶近似的。从观测者向发射源反向积分光子测地线，我们求解Sachs光学方程，并详细研究弱透镜汇聚、椭圆度和旋转。 首次，我们将这种分析应用于高分辨率的相对论N体模拟，该模拟一致地包含了广义相对论在大尺度和小尺度上的主要修正项。这些修正分别与规范选择的问题和后牛顿修正相关。 我们展示了弱透镜变量的角功率谱和单点概率分布函数，发现它们与可比较的牛顿模拟结果大致一致。然而，我们的几何方法更为稳健和灵活，因此可以一致地应用于非标准宇宙学和修改后的引力理论。 显示英文摘要

摘要： We present a numerical weak-lensing analysis that is fully relativistic and non-perturbative for the scalar part of the gravitational potential and first-order in the vector part, frame dragging. Integrating the photon geodesics backwards from the observer to the emitters, we solve the Sachs optical equations and study in detail the weak-lensing convergence, ellipticity and rotation. For the first time, we apply such an analysis to a high-resolution relativistic N-body simulation, which consistently includes the leading-order corrections due to general relativity on both large and small scales. These are related to the question of gauge choice and to post-Newtonian corrections, respectively. We present the angular power spectra and one-point probability distribution functions for the weak-lensing variables, which we find are broadly in agreement with comparable Newtonian simulations. Our geometric approach, however, is more robust and flexible, and can therefore be applied consistently to non-standard cosmologies and modified theories of gravity.