Related papers: Angular momentum near the black hole threshold in …
We study the gravitational collapse of a homogeneous time-dependent scalar field that, besides its coupling to curvature, it is also kinematically coupled to the Einstein tensor. This coupling is a part of the Horndeski theory and we…
We investigate critical phenomena during the gravitational collapse of a massive scalar field under two distinct semi-classical loop quantum gravity (LQG) approaches within spherical symmetry. Numerical simulations reveal that the massive…
We observe a condensate forming in the interior of a black hole (BH) during numerical simulations of gravitational collapse of a massless charged (complex) scalar field. The magnitude of the scalar field in the interior tends to a non-zero…
We show that spinless and neutral black holes in thermal equilibrium with radiation undergo fluctuations of charge and angular momentum. The corresponding spreads for a black hole in contact with charged scalar particles is calculated. The…
Semiclassical perturbations to the Reissner-Nordstrom metric caused by the presence of a quantized massive scalar field with arbitrary curvature coupling are found to first order in \epsilon = \hbar/M^2. The DeWitt-Schwinger approximation…
The discovery of quasars at increasingly large cosmological redshifts may favor "direct collapse" as the most promising evolutionary route to the formation of supermassive black holes. In this scenario, supermassive black holes form when…
A method is given to compute the stress-energy tensor for a massless minimally coupled scalar field in a spacetime where a black hole forms from the collapse of a spherically symmetric null shell in four dimensions. Part of the method…
We perform a numerical study of the critical regime at the threshold of black hole formation in the spherically symmetric, general relativistic collapse of collisionless matter. The coupled Einstein-Vlasov equations are solved using a…
We solve the Klein-Gordon equation for a scalar field, in the background geometry of a dust cloud collapsing to form a black hole, everywhere in the (1+1) spacetime: that is, both inside and outside the event horizon and arbitrarily close…
We consider black holes which form from an initially spherically symmetric super-Hubble perturbation of a cosmological background filled by a perfect fluid $p=w \rho$ with $w\in (0,1]$. Previous work has shown that when $w = 1/3$…
We study the gravitational collapse of a kink within spherical symmetry and the characteristic formulation of General Relativity. We explore some expected but elusive gravitational collapse issues which have not been studied before in…
We compute the quasi-bound state spectra of ultralight scalar and vector fields around rotating black holes. These spectra are determined by the gravitational fine structure constant $\alpha$, which is the ratio of the size of the black…
In transforming from Schwarzschild to Euclidean Rindler coordinates the Schwarzschild time transforms to a periodic angle. As is well-known, this allows one to introduce the Hawking temperature and is an origin of black hole thermodynamics.…
We present a new technique for time-domain numerical evolution of the scalar field generated by a pointlike scalar charge orbiting a black hole. Time-domain evolution offers an efficient way for calculating black hole perturbations,…
The gravitational collapse of a spherically symmetric massive core of a star in which the fluid component is interacting with a growing vacuum energy density filling a FLRW type geometry with an arbitrary curvature parameter is…
We study the collapse of a free scalar field in the Brans-Dicke model of gravity. At the critical point of black hole formation, the model admits two distinctive solutions dependent on the value of the coupling parameter. We find one…
We study numerically the fully nonlinear spherically-symmetric collapse of a self-gravitating, minimally-coupled, massless scalar field. Our numerical code is based on double-null coordinates and on free evolution of the metric functions…
We study gravitational collapse of rapidly rotating relativistic polytropes of the adiabatic index $\Gamma = 1.5$ and 2, in which the spin parameter $q \equiv J/M^{2} > 1$ where $J$ and $M$ are total angular momentum and gravitational mass,…
This paper investigates the dynamics of thin-shell in the presence of perfect fluid as well as the scalar field. We formulate the equations of motion using Israel thin-shell formalism by taking the interior and exterior regions of…
We present an exact collapsing solution to 2+1 gravity with a negative cosmological constant minimally coupled to a massless scalar field, which exhibits physical properties making it a candidate critical solution. We discuss its global…