Black hole perturbations in DHOST theories: master variables, gradient instability, and strong coupling
Black hole perturbations in DHOST theories: master variables, gradient instability, and strong coupling
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DOI：
10.1088/1475-7516/2021/08/013
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发表时间：
2021-06
影响因子：
6.4
通讯作者：
Kazufumi Takahashi;H. Motohashi
中科院分区：
文献类型：
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作者：
Kazufumi Takahashi;H. Motohashi
研究了简并高阶标量张量（DHOST）理论中具有隐身标量毛的静态和球对称黑洞解的线性摄动。我们澄清了主变量，并推导了奇偶宇称摄动的二次拉格朗日。结果表明，偶模态通常受到梯度不稳定性的困扰，否则扰动将是强耦合的。
We study linear perturbations about static and spherically symmetric black hole solutions with stealth scalar hair in degenerate higher-order scalar-tensor (DHOST) theories. We clarify master variables and derive the quadratic Lagrangian for both odd- and even-parity perturbations. It is shown that the even modes are in general plagued by gradient instabilities, or otherwise the perturbations would be strongly coupled.