相关论文: Do black hole shadows merge?

We elucidate how black holes form in trans-Planckian collisions. In the rest frame of one of the incident particles, the gravitational field of the other, which is rapidly moving, looks like a gravitational shock wave. The shock wave…

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed "black stars". Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic…

It was argued recently that there exists an unexpected phenomenon, the reflection of incoming particles on the event horizon of black holes (Kuchiev(2003)). This means that a particle approaching the black hole can bounce back into the…

We consider the gravitational collapse of a dust cloud in an asymptotically anti de Sitter spacetime in which points connected by a discrete subgroup of an isometry subgroup of anti de Sitter spacetime are identified. We find that black…

In this chapter I focus on asking and answering the following questions: (1) What is a black hole? Answer: There are three types of black holes, namely mathematical black holes, physical black holes and astrophysical black holes. An…

In this paper we propose a model for the formation of the cosmological voids. We show that cosmological voids can form directly after the collapse of extremely large wavelength perturbations into low-density black holes or cosmological…

The presence of a bright "photon ring" surrounding a dark "black hole shadow" has been discussed as an important feature of the observational appearance of emission originating near a black hole. We clarify the meaning and relevance of…

We study the optical appearance of a de Sitter-Schwarzschild black hole and its distinguishability from a Schwarzschild black hole. By exploring various accretion models and emission profiles, we investigate the impact of different…

We show that, away from the axis of symmetry, no continuous degeneration exists between the shadows of observers at any point in the exterior region of any Kerr-Newman black hole spacetime of unit mass. Therefore, except possibly for…

The cosmic censorship conjecture posits that singularities forming to the future of a regular Cauchy surface are hidden by an event horizon. Consequently any topological structures will ultimately collapse within the horizon of a set of…

We study black holes produced by the collapse of a spherically symmetric charged scalar field in asymptotically flat space. We employ a late time expansion and show decaying fluxes of radiation through the event horizon imply the black hole…

We examine the gravitational collapse and black hole formation of multiple non--spherical configurations constructed from Szekeres dust models with positive spatial curvature that smoothly match to a Schwarzschild exterior. These…

The coalescence of supermassive black hole binaries occurs via the emission of gravitational waves, that can impart a substantial recoil to the merged black hole. We consider the energy dissipation, that results if the recoiling black hole…

This paper presents results of a series of numerical N-body experiments that describe the merging of galaxy pairs containing a massive black hole in their core. The aim is to study the orbital evolution of the two black holes through the…

We study the homogeneous gravitational collapse of a spherical cloud of matter in a super-renormalizable and asymptotically free theory of gravity. We find a picture that differs substantially from the classical scenario. The central…

We numerically calculate the spacetime describing the formation and evaporation of a regular black hole in 2D dilaton gravity. The apparent horizons evaporate smoothly in finite time to form a compact trapped region. We nevertheless see…

Recently, new exploratory channels have opened up for the physics of highly compact objects, such as gravitational waves and black hole shadows. Moreover, more precise analysis and observations are now possible in the physics of accretion…

We model the collapse of a spherically symmetric, constant density, pressureless shell onto a preexisting black hole. Contrary to a recent claim of Liu and Zhang (2009), we show that an observer at infinity never sees any part of the shell…

Cosmic voids are known as underdense substructures of the cosmic web that cover a large volume of the Universe. It is known that cosmic voids contain a small number of dark matter halos, so the existence of primordial black holes (PBHs) in…

The existence of exact solutions which represent a lattice of black holes at a scalar-field-dominated cosmological bounce suggests that black holes could persist through successive eras of a cyclic cosmology. Here we explore some remarkable…