Non-linear stability of $\alpha'$-corrected Friedmann equations

TL;DR

This paper investigates the non-linear stability of fixed-point solutions in $ ext{O}(d,d)$ invariant cosmology with $ ext{alpha'}$ corrections, analyzing perturbations and their invariance properties.

Contribution

It provides a detailed non-linear stability analysis of $ ext{alpha'}$-corrected cosmological solutions and explores perturbation invariance in duality-invariant frameworks.

Findings

Revisits and confirms compatibility with linear perturbation results

Establishes existence of time-reparameterization invariant variables

Analyzes formal aspects of cosmological perturbations in duality invariant models

Abstract

We study the non-linear stability of fixed-point solutions to the $\alpha'$-exact equations from O$(d,d)$ invariant cosmology, with and without matter perturbations. Previous non-linear analysis in the literature is revisited, and its compatibility with known linear perturbation results is shown. Some formal aspects of cosmological perturbations in duality invariant cosmology are discussed, and we show the existence of time-reparameterization invariant variables for perturbations.