相关论文: Numerical simulations of stellar collapse in scala…
We present a code for numerical simulations of the collapse of regular initial data to a black hole in null coordinates. We restrict to twist-free axisymmetry with scalar field matter. Our coordinates are $(u,x,y,\varphi)$, where the…
The applicability of the highly idealized secondary infall model to `realistic' initial conditions is investigated. The collapse of proto-halos seeded by $3\sigma$ density perturbations to an Einstein--de Sitter universe is studied here for…
Gravitational collapse into a black hole has been extensively studied with classical sources. We develop a new formalism to simulate quantum fields forming a black hole. This formalism utilizes well-established techniques used for classical…
The recent discovery of gravitational radiation from merging black holes poses a challenge of how to organize the electromagnetic follow-up of gravitational-wave events as well as observed bursts of neutrinos. We propose a technique to…
We explore a collapsing cosmology driven by a scalar field which is minimally coupled to gravity in a spatially at and spherically symmetric, isotropic and homogeneous space-time, with a variable timescale that avoids the final singularity.…
We describe results of a numerical calculation of circularly symmetric scalar field collapse in three spacetime dimensions with negative cosmological constant. The procedure uses a double null formulation of the Einstein-scalar equations.…
In this paper, we present the results of 3-dimensional collapse simulations of rotating stars for a range of stellar progenitors. We find that for the fastest spinning stars, rotation does indeed modify the convection above the…
Gravitational wave bursts in the formation of neutron stars and black holes in energetic core-collapse supernovae (CC-SNe) are of potential interest to LIGO-Virgo and KAGRA. Events nearby are readily discovered using moderately sized…
We examine the nonlinear structure of gravitationally collapsed objects that form in our simulations of wavelike cold dark matter ($\psi$DM), described by the Schr\"{o}dinger-Poisson (SP) equation with a particle mass $\sim 10^{-22} {\rm…
We have developed a new numerical code to simulate the joint evolution of a massive black hole (MBH) and a surrounding stellar cluster at the center of a galaxy. The physics treated in the simulations include: 2-body relaxation, stellar…
We study the collapse of a self-gravitating and radiating shell. Matter constituting the shell is quantized and the construction is viewed as a semiclassical model of possible black hole formation. It is shown that the shell internal…
Recent developments in the field of gravitational physics, including the emergence of gravitational wave astronomy, black hole images, and more accurate telescopes, have allowed us to probe the strong-field character of gravity in a novel…
Cosmic structures at large scales represent the earliest and most extended form of matter condensation. In this lecture we review the application of the methods and concepts of modern statistical physics to these structures. This leads to a…
The quest for the supernova explosion mechanism has been one of the outstanding challenges in computational astrophysics for several decades. Simulations have now progressed to a stage at which the solution appears close and neutrino and…
Among the possible extensions of General Relativity that have been put forward in order to address some long standing issues in our understanding of the Universe, Scalar-Tensor Theories have received a lot of attention for their simplicity.…
Several classes of conformally-flat and spherically symmetric exact solutions to the Einstein field equations coupled with either a massless scalar field or a radiation fluid are given, and their main properties are studied. It is found…
Gravitational collapse of radiation in an anti-de Sitter background is studied. For the spherical case, the collapse proceeds in much the same way as in the Minkowski background, i.e., massless naked singularities may form for a highly…
Observed molecular clouds often appear to have very low star formation efficiencies and lifetimes an order of magnitude longer than their free-fall times. Their support is attributed to the random supersonic motions observed in them. We…
We present the first search for gravitational waves from sub-solar mass compact-binary mergers which allows for non-negligible orbital eccentricity. Sub-solar mass black holes are a signature of primordial origin black holes, which may be a…
In the centre of our galaxy lies a super-massive black hole, identified with the radio source Sagittarius A*. This black hole has an estimated mass of around 4 million solar masses. Although Sagittarius A* is quite dim in terms of total…