Linear stability of Einstein and de Sitter universes in the quadratic theory of modified gravity
Mudhahir Al-Ajmi
SciPost Phys. Proc. 4, 012 (2021) · published 13 August 2021
- doi: 10.21468/SciPostPhysProc.4.012
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Proceedings event
4th International Conference on Holography, String Theory and Discrete Approach in Hanoi
Abstract
We consider the Einstein static and the de Sitter universe solutions and examine their instabilities in a subclass of quadratic modified theories for gravity. This modification proposed by Nash is an attempt to generalize general relativity. Interestingly, we discover that the Einstein static universe is unstable in the context of the modified gravity. In contrast to Einstein static universe, the de Sitter universe remains stable under metric perturbation up to the second order.