AT4 - Massive gravity, Horndeski theory and other "ghost-free" models of modified gravity |
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Speaker |
MAEDA, Kei-ichi |
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Coauthors |
Aoki, Katsuki; Misonoh, Yosuke; Okawa, Hirotada |
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Massive Graviton Geon in Bigravity Theory |
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Abstract |
We find vacuum solutions such that massive gravitons are confined in a local spacetime region by their gravitational energy in asymptotically flat spacetimes in the context of the bigravity theory. We call such self-gravitating objects massive graviton geons. The basic equations are reduced to the Schroedinger-Poisson equations with the tensor ``wavefunction'' in the Newtonian limit. We obtain a non-spherically symmetric solution as well as a spherically symmetric solution. The energy eigenvalue of the Schroedinger equation in the non-spherical solution is smaller than that in the spherical solution. This suggests that the non-spherically symmetric solution is the ground state of the massive graviton geon. The massive graviton geons may decay in time due to emissions of gravitational waves but this timescale is quite long when the massive gravitons are non-relativistic and then the geons can be long-lived. We also discuss the ultralight dark matter scenario by use of the massive graviton geons. |
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