Quasinormal modes, stability and shadows of a black hole in the 4D Einstein–Gauss–Bonnet gravity
Quasinormal modes, stability and shadows of a black hole in the 4D Einstein–Gauss–Bonnet gravity
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DOI：
10.1140/epjc/s10052-020-08639-8
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
R. Konoplya;R. Konoplya;A. Zinhailo
中科院分区：
文献类型：
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作者：
R. Konoplya;R. Konoplya;A. Zinhailo
最近，人们提出了一种d维正则化方法，该方法可以使引力的非平凡维爱因斯坦-高斯-博内（EGB）有效描述绕过洛夫洛克定理，避免了Ostrogradsky不稳定性。后来证明，正则化仅对一些广泛但有限的度量类是可能的，Aoki等人（arXiv:2005.03859）制定了一个定义良好的四维EGB理论，该理论以理论上一致和观测上可行的方式打破了洛伦兹不变性。第一个朴素方法的黑洞解也被证明是定义良好的理论的精确解。本文计算了标量扰动、电磁扰动和引力扰动的拟正态模态，并在高斯-博内修正下求出了球对称和渐近平坦黑洞的阴影半径。我们证明当（）时黑洞是引力稳定的。外范围的不稳定性为斜向不稳定性，并在高多极数时发展。阴影的半径非常精确地服从线性规律。
Recently aD-dimensional regularization approach leading to the non-trivial-dimensional Einstein–Gauss–Bonnet (EGB) effective description of gravity was formulated which was claimed to bypass the Lovelock’s theorem and avoid Ostrogradsky instability. Later it was shown that the regularization is possible only for some broad, but limited, class of metrics and Aoki et al. ( arXiv:2005.03859 ) formulated a well-defined four-dimensional EGB theory, which breaks the Lorentz invariance in a theoretically consistent and observationally viable way. The black-hole solution of the first naive approach proved out to be also the exact solution of the well-defined theory. Here we calculate quasinormal modes of scalar, electromagnetic and gravitational perturbations and find the radius of shadow for spherically symmetric and asymptotically flat black holes with Gauss–Bonnet corrections. We show that the black hole is gravitationally stable when (). The instability in the outer range is the eikonal one and it develops at high multipole numbers. The radius of the shadowobeys the linear law with a remarkable accuracy.