MG13 - Talk detail |
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Participant |
Motohashi, Hayato | |||||||
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Institution |
Research Center for the Early Universe, University of Tokyo - Hongo, 7-3-1 - Bunkyo-ku - Tokyo - Japan | |||||||
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Session |
AT4 |
Accepted |
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Order |
Time |
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Talk |
Oral abstract |
Title |
Black hole perturbation in modified gravity theories | |||||
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Abstract |
We study linear perturbations around the static and spherically symmetric spacetime for the following modified gravitational theories: f(R,C) theories, non/dynamical Chern-Simons gravity, and Galileon theories, that is the most general scalar-tensor theory with second-order field equations. By an explicit construction, we show that Hamiltonian for the perturbation variables is not bounded from below in general, suggesting that such a background spacetime is unstable against perturbations. This gives a strong limit on a phenomenological gravitational models. We also provide a necessary and sufficient condition for the theories to avoid such instability. |
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