Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
Theoretical Astrophysics, IAAT, University of Tübingen, 72076 Tübingen, Germany.
Phys Rev Lett. 2022 Mar 18;128(11):111103. doi: 10.1103/PhysRevLett.128.111103.
Recent work applying the notion of pseudospectrum to gravitational physics showed that the quasinormal mode spectrum of black holes is unstable, with the possible exception of the longest-lived (fundamental) mode. The fundamental mode dominates the expected signal in gravitational wave astronomy, and there is no reason why it should have privileged status. We compute the quasinormal mode spectrum of two model problems where the Schwarzschild potential is perturbed by a small "bump" consisting of either a Pöschl-Teller potential or a Gaussian, and we show that the fundamental mode is destabilized under generic perturbations. We present phase diagrams and study a simple double-barrier toy problem to clarify the conditions under which the spectral instability occurs.
最近将伪谱概念应用于引力物理学的研究表明，黑洞的拟正则模谱是不稳定的，除了最长寿（基本）模式之外。基本模式在引力波天文学中主导着预期的信号，没有理由认为它具有特权地位。我们计算了两个模型问题的拟正则模谱，其中 Schwarzschild 势被一个由 Pöschl-Teller 势或高斯函数组成的小“凸起”所扰动，我们表明在一般扰动下基本模式是不稳定的。我们给出了相图，并研究了一个简单的双势垒玩具问题，以澄清发生谱不稳定的条件。
