English

Stability of the Self-accelerating Universe in Massive Gravity

High Energy Physics - Theory 2015-06-16 v2 Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology

Abstract

We study linear perturbations around time dependent spherically symmetric solutions in the Lambda_3 massive gravity theory, which self-accelerate in the vacuum. We find that the dynamics of the scalar perturbations depend on the coordinate choice for the background solutions. For particular choices of coordinates there is a symmetry enhancement, leaving no propagating scalar degrees of freedom at linear order in perturbations. In contrast, any other coordinate choice propagates a single scalar mode. We find that the Hamiltonian of this scalar mode is unbounded from below for all self-accelerating solutions, signalling an instability.

Keywords

Cite

@article{arxiv.1305.4950,
  title  = {Stability of the Self-accelerating Universe in Massive Gravity},
  author = {Nima Khosravi and Gustavo Niz and Kazuya Koyama and Gianmassimo Tasinato},
  journal= {arXiv preprint arXiv:1305.4950},
  year   = {2015}
}

Comments

references added; accepted for publication in JCAP