English

The radiation instability in modified gravity

General Relativity and Quantum Cosmology 2021-04-21 v2 High Energy Physics - Theory

Abstract

We study the problem of the instability of inhomogeneous radiation universes in quadratic lagrangian theories of gravity written as a system of evolution equations with constraints. We construct formal series expansions and show that the resulting solutions have a smaller number of arbitrary functions than that required in a general solution. These results continue to hold for more general polynomial extensions of general relativity.

Keywords

Cite

@article{arxiv.2012.05850,
  title  = {The radiation instability in modified gravity},
  author = {Spiros Cotsakis and Dimitrios Trachilis},
  journal= {arXiv preprint arXiv:2012.05850},
  year   = {2021}
}

Comments

v2: 34 pages, references added, version to match the published one

R2 v1 2026-06-23T20:52:53.667Z