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arXiv · 1305.4950

Stability of the Self-accelerating Universe in Massive Gravity

Nima Khosravi·Gustavo Niz·Kazuya Koyama·Gianmassimo Tasinato
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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.

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Nima Khosravi, Gustavo Niz, Kazuya Koyama, Gianmassimo Tasinato. 2013-08-13. Stability of the Self-accelerating Universe in Massive Gravity. https://doi.org/10.1088/1475-7516%2F2013%2F08%2F044

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