Related papers: Black hole formation in gravitational collapse and…
We study the physical process of gravitational collapse of a perfect fluid with a linear isentropic equation of state $p = k \rho, \ -1/3 < k \leq 1$. We consider a model with ansatz $v'(t,r)/v(t,r) = \xi'(r)$ that give rise to a family of…
We calculate the first dynamical evolutions of merging black hole-neutron star binaries that construct the combined black hole-neutron star spacetime in a general relativistic framework. We treat the metric in the conformal flatness…
In this work, we explore the production of primordial black holes (PBHs) within the context of $\alpha$-attractor inflationary models, focusing on the preheating phase following inflation. During this phase, self-resonance instabilities…
This article presents a new model-independent constraint for bouncing black hole geometries. Using the thin shell formalism, this constraint sets a bound on the minimal allowed radius of the time-like surface of the collapsing star at the…
The description of a point mass in general relativity (GR) is given in the framework of the field formulation of GR where all the dynamical fields, including the gravitational field, are considered in a fixed background spacetime. With the…
We discuss 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. The influence of the variable vacuum in the collapsing core is…
We launch a fully relativistic study of the formation of supermassive black holes via the collapse of supermassive stars. Here we initiate our investigation by analyzing the secular evolution of supermassive stars up to the onset of…
We introduce a new method for numerically evolving the full Einstein field equations in situations where the spacetime is dominated by a known background solution. The technique leverages the knowledge of the background solution to subtract…
We study the final state of the gravitational collapse of uniformly rotating supramassive neutron stars by axisymmetric simulations in full general relativity. The rotating stars provided as the initial condition are marginally stable…
See thesis for complete abstract. Primordial black holes (PBHs) can form in the early universe, and there are several mass windows in which their abundance today may be large enough to comprise a significant part of the dark matter density.…
The latest detection of GW231123, a binary black hole (BH) merger with exceptionally large masses and high spins for the incoming components, has been suggested as a smoking gun for hierarchical formation. In this scenario, a first…
Supermassive black holes (SMBHs) found in the centers of many galaxies have been recognized to play a fundamental active role in the cosmological structure formation process. In hierarchical formation scenarios, SMBHs are expected to form…
The composition as well as the very existence of the interior of a Schwarzschild black hole (BH) remains at the forefront of open problems in fundamental physics. To address this issue, we turn to Hawking's "principle of ignorance", which…
The formation of cosmological black holes is investigated using the functional Schroedinger equation as observed by an asymptotic observer, assuming a spherical domain wall collapse process. The mass formula of the Sultana-Dyer black hole…
We present a suite of the first 3D GRMHD collapsar simulations, which extend from the self-consistent jet launching by an accreting Kerr black hole (BH) to the breakout from the star. We identify three types of outflows, depending on the…
We show that four-dimensional black holes become stable below certain mass when the Einstein-Hilbert action is supplemented with higher-curvature terms. We prove this to be the case for an infinite family of ghost-free theories involving…
In this paper, we study the formation and dynamical evolution of black hole-black hole (BH-BH) binaries in young star clusters (YSCs), by means of N-body simulations. The simulations include metallicity-dependent recipes for stellar…
The existence of black holes (BHs) of mass ~ 10^{9} M_sun at z > 6 is a big puzzle in astrophysics because even optimistic estimates of the accretion time are insufficient for stellar mass BHs of ~ 10 M_sun to grow into such supermassive…
We investigate an analog model of charged black hole (BH) formation using the framework of classical percolation. By analyzing the scaling behavior of key quantities, including surface gravity and Komar mass, we establish a robust…
The dynamical processes involving stellar-remnant black holes (BH) in stellar clusters has always drawn attention due to the BHs' potential in a number of astrophysical phenomena, especially the dynamical formation of binary black holes…