Very compact objects probe extreme gravitational fields and may be the key to understand
outstanding puzzles in fundamental physics. These include the nature of dark matter, the …

We introduce a family of solutions of Einstein's gravity minimally coupled to an anisotropic
fluid, describing asymptotically flat black holes with “hair” and a regular horizon. These …

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 …

It has been shown, via specific examples and a pseudospectrum analysis, that the black
hole quasinormal spectra are unstable. The implication of such a result for gravitational …

The recent observation of the shadow of the supermassive black hole M87*, located at the
center of the M87 galaxy, by the Event Horizon Telescope Collaboration has opened up a …

The well-known correspondence between quasinormal modes of any stationary, spherically
symmetric and asymptotically flat or de Sitter black hole and parameters of the circular null …

We study the stability of quasinormal modes (QNM) in asymptotically flat black hole
spacetimes by means of a pseudospectrum analysis. The construction of the Schwarzschild …

We show that perturbations of a scalar field in the background of the spherically symmetric
black hole obtained with the Starobinsky-Bel-Robinson Gravity are unstable unless the …

In this paper, we investigate the quasinormal mode (QNM) spectra for the scalar perturbation
over the quantum-corrected black hole (BH) known as the quantum Oppenheimer-Snyder …

In this work, we wish to address the question—whether the quasinormal modes, the
characteristic frequencies associated with perturbed black hole spacetimes, central to the …