Related papers: Particle creation in (2+1) circular dust collapse
In this paper we will examine the consequence of a canonical theory of quantum dust collapse in 2+1 dimensions. The solution of the WDW equation describing the collapse indicates that collapsing shells outside the apparent horizon are…
If we consider the gravitational collapse of a material object to a black hole, we would expect, for ranges of mass where a black hole would form, the following scenario. A large enough object would collapse classically until an event…
When two point particles, coupled to three dimensional gravity with a negative cosmological constant, approach each other with a sufficiently large center of mass energy, then a BTZ black hole is created. An explicit solution to the…
We develop the canonical theory of gravitational collapse in 2+1 dimensions with a negative cosmological constant and obtain exact solutions of the Wheeler--DeWitt equation regularized on a lattice. We employ these solutions to derive the…
This paper considers the quantum collapse of infinitesimally thin dust shells in 2+1 gravity. In 2+1 gravity a shell is no longer a sphere but a ring of matter. The classical equation of motion has been considered by Peleg and Steif and…
An expanding closed universe filled with radiation can either recollapse or tunnel to the regime of unbounded expansion, if the cosmological constant is nonzero. We re-examine the question of particle creation during tunneling, with the…
We investigate scalar particle creation in a set of bouncing models where the bounce occurs due to quantum cosmological effects described by the Wheeler-DeWitt equation. The scalar field can be either conformally or minimally coupled to…
Black holes (BHs) play a central role in physics. However, gathering observational evidence for their existence is a notoriously difficult task. Current strategies to quantify the evidence for BHs all boil down to looking for signs of…
Recent studies have shown that quantum gravity introduces important corrections to the process of spherically symmetric gravitational collapse expected from general relativity. In particular, instead of falling into a central singularity,…
We study here the gravitational collapse of dust in $(2+1)$-dimensional spacetimes for the formation of black holes (BH) and naked singularities (NS) as final states in a modified theory of gravity, with vanishing cosmological constant.…
We study the black hole particle production in a regular spacetime metric obtained in a minisuperspace approach to loop quantum gravity. In different previous papers the static solution was obtained and shown to be singularity-free and…
We consider the evaporation of the (shell focusing) naked singularity formed during the self-similar collapse of a marginally bound inhomogeneous dust cloud, in the geometric optics approximation. We show that, neglecting the back reaction…
A simple, geometrical construction is given for three-dimensional spacetimes with negative cosmological constant that contain two particles colliding head-on. Depending on parameters like particle masses and distance, the combined geometry…
Hawking has predicted that the formation of a black hole by gravitational collapse causes quantum particle creation and the spectrum of the particles is almost thermal. This phenomenon is called the Hawking radiation. Recently, it has been…
We examine the gravitational collapse of spherically symmetric inhomogeneous dust in (2+1) dimensions, with cosmological constant. We obtain the analytical expressions for the interior metric. We match the solution to a vacuum exterior. We…
Creation of thermal distribution of particles by a black hole is independent of the detail of gravitational collapse, making the construction of the eternal horizons suffice to address the problem in asymptotically flat spacetimes. For…
Recently, the possibility was pointed out by one of the present authors and his collaborators that an effective naked singularity referred to as "a visible border of spacetime" is generated by high-energy particle collision in the context…
We numerically study the dynamics of an imploding hollow cylinder composed of dust. Since there is no cylindrical black hole in 4-dimensional spacetime with physically reasonable energy conditions, a collapsed dust cylinder involves a naked…
Spherically symmetric, null dust clouds, like their time-like counterparts, may collapse classically into black holes or naked singularities depending on their initial conditions. We consider the Hamiltonian dynamics of the collapse of an…
The collapse of thin dust shells in 2+1 dimensional gravity with and without a cosmological constant in analyzed. A critical value of the shell's mass as a function of its radius and position is derived. For $\Lambda < 0$, a naked…