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arXiv · 2211.15873

Spin-2 dark matter from anisotropic Universe in bigravity

Yusuke Manita·Katsuki Aoki·Tomohiro Fujita·Shinji Mukohyama
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Abstract

Bigravity is one of the natural extensions of general relativity and contains an additional massive spin-2 field which can be a good candidate for dark matter. To discuss the production of spin-2 dark matter, we study fixed point solutions of the background equations for axisymmetric Bianchi type-I Universes in two bigravity theories without Boulware-Deser ghost, i.e., Hassan-Rosen bigravity and Minimal Theory of Bigravity. We investigate the local and global stability of the fixed points and classify them. Based on the general analysis, we propose a new scenario where spin-2 dark matter is produced by the transition from an anisotropic fixed point solution to isotropic one. The produced spin-2 dark matter can account for all or a part of dark matter and can be directly detected by laser interferometers in the same way as gravitational waves.

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Yusuke Manita, Katsuki Aoki, Tomohiro Fujita, Shinji Mukohyama. 2022-11-29. Spin-2 dark matter from anisotropic Universe in bigravity. https://doi.org/10.1103/physrevd.107.104007

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