On a Growing Transverse Mode as a Post-Newtonian Effect in the Large-Scale Structure Formation

TL;DR

This paper identifies a new post-Newtonian transverse mode in gravitational instability, which could influence large-scale structure formation and observable anisotropies in the cosmic microwave background.

Contribution

It introduces a novel post-Newtonian transverse mode in cosmological perturbation theory using Lagrangian formulation, expanding understanding of structure formation effects.

Findings

Existence of a new growing transverse mode in gravitational instability

Potential observational signatures in CMB anisotropy

Formulation within cosmological post-Newtonian approximation

Abstract

We point out the existence of a new type of growing transverse mode in the gravitational instability. This appears as a post-Newtonian effect to Newtonian dynamics. We demonstrate this existence by formulating the Lagrangian perturbation theory in the framework of the cosmological post-Newtonian approximation in general relativity. Such post-Newtonian order effects might produce characteristic appearances of large-scale structure formation, for example, through the observation of anisotropy of the cosmic microwave background radiation (CMB).