Constraint on ghost-free bigravity from gravitational Cherenkov radiation
Constraint on ghost-free bigravity from gravitational Cherenkov radiation
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DOI：
10.1103/physrevd.94.064059
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发表时间：
2016-05
影响因子：
5
通讯作者：
Rampei Kimura;Takahiro Tanaka;Kazuhiro Yamamoto;Yasuho Yamashita
中科院分区：
文献类型：
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作者：
Rampei Kimura;Takahiro Tanaka;Kazuhiro Yamamoto;Yasuho Yamashita
本文研究了无重影双引力模型中背景解健康分支中的引力切伦科夫辐射。在这个模型中，由于色散关系的修改，每个偏振模式可以具有亚光速的相速度，引力切伦科夫辐射可能从相对论粒子发射。在本文中，我们推导出引力切伦科夫辐射过程发生的条件和估计的能量发射率为每一个偏振模式。我们发现，即使从一个高能宇宙射线发出的引力切伦科夫辐射是足够的抑制引力子的有效质量小于100 eV，和暗物质耦合到隐藏的度量的双引力模型，因此是一致的高能宇宙射线的观测。
We investigate gravitational Cherenkov radiation in a healthy branch of background solutions in the ghost-free bigravity model. In this model, because of the modification of dispersion relations, each polarization mode can possess subluminal phase velocities, and the gravitational Cherenkov radiation could be potentially emitted from a relativistic particle. In the present paper, we derive conditions for the process of the gravitational Cherenkov radiation to occur and estimate the energy emission rate for each polarization mode. We found that the gravitational Cherenkov radiation emitted even from an ultrahigh energy cosmic ray is sufficiently suppressed for the graviton's effective mass less than 100 eV, and the bigravity model with dark matter coupled to the hidden metric is therefore consistent with observations of high energy cosmic rays.