论文标题
关于一般性的拉格朗日扰动理论及其非扰动概括
On general-relativistic Lagrangian perturbation theory and its non-perturbative generalization
论文作者
论文摘要
牛顿拉格朗日扰动理论是一个广泛使用的框架，用于研究非线性制度中宇宙学的结构形成。我们回顾了这种扰动方法的一般性相关性表述，强调了已经开发出广泛的形式主义的结果，包括其他方面：RICCI和Weyl曲率的非扰动建模，重力波和压力支持的流体。我们讨论了与Szekeres II类相关的精确解决方案的子案例，并以精确的平均模型为RICCI-FLAT LTB模型。后者构成了概括的基础，然后我们就一项超越相对论的拉格朗日扰动理论的方案提出了概括，该方案对全球均质 - 异位背景宇宙学。这种新的近似不涉及均匀的参考背景，它包含Szekeres I类（因此是一般LTB模型）作为精确的子案例。最重要的是，这种新的近似允许结构与不断发展的“背景宇宙学”的相互作用，被认为是一种空间平均模型，因此包括宇宙学的反应。
The Newtonian Lagrangian perturbation theory is a widely used framework to study structure formation in cosmology in the nonlinear regime. We review a general-relativistic formulation of such a perturbation approach, emphasizing results on already developed extensive formalism including among other aspects: the non-perturbative modeling of Ricci and Weyl curvatures, gravitational waves and pressure-supported fluids. We discuss subcases of exact solutions related to Szekeres Class II and, as exact average model, Ricci-flat LTB models. This latter forms the basis of a generalization that we then propose in terms of a scheme that goes beyond the relativistic Lagrangian perturbation theory on a global homogeneous-isotropic background cosmology. This new approximation does not involve a homogeneous reference background and it contains Szekeres class I (and thus general LTB models) as exact subcases. Most importantly, this new approximation allows for the interaction of structure with an evolving `background cosmology', conceived as a spatial average model, and thus includes cosmological backreaction.
