# Higher order perturbations of Anti-de Sitter space and time-periodic solutions of vacuum Einstein equations

## TL;DR

This paper investigates nonlinear gravitational perturbations of Anti-de Sitter space, providing evidence for the existence of time-periodic vacuum solutions bifurcating from linear eigenfrequencies, with implications for stability analysis.

## Contribution

It demonstrates the existence of globally regular, time-periodic vacuum solutions in AdS space arising from nonlinear perturbations, extending understanding of AdS stability.

## Key findings

- Time-periodic solutions bifurcate from linear eigenfrequencies.
- Number of solution families equals eigenfrequency multiplicity.
- Preliminary results suggest stability features of AdS space.

## Abstract

Motivated by the problem of stability of Anti-de Sitter (AdS) spacetime, we discuss nonlinear gravitational perturbations of maximally symmetric solutions of vacuum Einstein equations in general and the case of AdS in particular. We present the evidence that, similarly to the self-gravitating scalar field at spherical symmetry, the negative cosmological constant allows for the existence of globally regular, asymptotically AdS, time-periodic solutions of vacuum Einstein equations whose frequencies bifurcate from linear eigenfrequencies of AdS. Interestingly, our preliminary results indicate that the number of one parameter families of time-periodic solutions bifurcating from a given eigenfrequency equals the multiplicity of this eigenfrequency.