论文标题
所有尺度上的宇宙学重力：简单方程，所需条件和修饰重力的框架
Cosmological gravity on all scales: simple equations, required conditions, and a framework for modified gravity
论文作者
论文摘要
通常对重力的宇宙学现象学进行了两个限制研究：相对论扰动理论（大尺度）和牛顿重力（对于较小的，非线性的，尺度）。独立于模型的修饰重力的传统方法基于扰动理论，因此请勿应用于非线性尺度。未来的调查（例如欧几里得）将在线性和非线性尺度上产生重要的数据，因此需要一种新的方法来通过同时使用这些调查中的所有数据来限制独立于模型的修改重力。我们使用Foredmann方法中的高阶方程来得出一组“简单1PF”（第一个FRIEDMANN）方程，这些方程在小规模和大型限制中都适用，我们检查了所需的条件，使得没有中间方案，这意味着这些简单方程在所有尺度上都是有效的。我们演示了此处得出的简单1PF方程式如何用作适用于所有宇宙学量表的修饰重力的模型独立框架，并且我们提出了一种用于确定在这种方法下累积哪些修饰的重力理论的算法。这种修改的重力框架为现象学N体模拟提供了一种严格的方法，并为始终使用即将进行的调查中的所有数据铺平了道路，以独立于模型的方式来限制修饰的重力。
The cosmological phenomenology of gravity is typically studied in two limits: relativistic perturbation theory (on large scales) and Newtonian gravity (required for smaller, non-linear, scales). Traditional approaches to model-independent modified gravity are based on perturbation theory, so do not apply on non-linear scales. Future surveys such as Euclid will produce significant data on both linear and non-linear scales, so a new approach is required to constrain model-independent modified gravity by simultaneously using all of the data from these surveys. We use the higher order equations from the post-Friedmann approach to derive a single set of "simple 1PF" (first post-Friedmann) equations that apply in both the small scale and large scale limits, and we examine the required conditions for there to be no intermediate regime, meaning that these simple equations are valid on all scales. We demonstrate how the simple 1PF equations derived here can be used as a model-independent framework for modified gravity that applies on all cosmological scales, and we present an algorithm for determining which modified gravity theories are subsumed under this approach. This modified gravity framework provides a rigorous approach to phenomenological N-body simulations, and paves the way to consistently using all of the data from upcoming surveys to constrain modified gravity in a model-independent fashion.
