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arXiv · 1707.02004

Stable cosmology in ghost-free quasidilaton theory

A. Emir Gumrukcuoglu·Kazuya Koyama·Shinji Mukohyama
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Abstract

We present a novel cosmological solution in the framework of extended quasidilaton theory which underwent scrutiny recently. We only consider terms that do not generate the Boulware-Deser degree of freedom, hence the "ghost-free" quasidilaton theory, and show three new branches of cosmological evolution therein. One of the solutions passes the perturbative stability tests. This new solution exhibits a late time self-acceleration and all graviton polarizations acquire masses that converge to a constant in the asymptotic future. Moreover, all modes propagate at the speed of light. We propose that this solution can be used as a benchmark model for future phenomenological studies.

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A. Emir Gumrukcuoglu, Kazuya Koyama, Shinji Mukohyama. 2017-07-07. Stable cosmology in ghost-free quasidilaton theory. https://doi.org/10.1103/physrevd.96.044041

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