This is an unconventional review article on spectral problems in black hole perturbation
theory. Our purpose is to explain how to apply various known techniques in quantum …

We review nonsingular static, spherically symmetric solutions of general relativity with
minimally coupled scalar fields. Considered are wormholes and regular black holes (BHs) …

Pole-skipping is a property of gravitational waves dictated by their behaviour at horizons of
black holes. It stems from the inability to unambiguously impose ingoing boundary …

A bstract The static Love numbers of four-dimensional asymptotically flat, isolated, general-
relativistic black holes are known to be identically vanishing. The Love symmetry proposal …

Black holes can be electromagnetically charged or carry vector charge from new
fundamental fields. Their response to small fluctuations is of paramount importance to study …

In this paper, the gauge choices in general spherically symmetric spacetimes are explored.
In particular, we construct the gauge invariant variables and the master equations for both …

The response of black holes to companions is of fundamental importance in the context of
their dynamics and of gravitational-wave emission. Here, we explore the effect of charge on …

Two remarkable facts about Jackiw–Teitelboim (JT) two-dimensional dilaton-gravity have
been recently uncovered: this theory is dual to an ensemble of quantum mechanical …

There is a claim that a static-charged black hole (Reissner-Nordström black hole) can be
overcharged by absorbing a charged test particle. If it is true, it might give a counter example …

Perturbations and eikonal instabilities of black holes and branes in the Einstein-Gauss-
Bonnet theory and its Lovelock generalization were considered in the literature for several …