相关论文: Black hole formation from axion stars
The spin of a number of black holes (BHs) in binary systems has been measured. In the case of BHs found in low-mass X-ray binaries (LMXBs) the observed values are in agreement with some theoretical predictions based on binary stellar…
We solve dynamical equations of motion to determine the conditions under which an over-dense region in the early universe will lead to collapse to a black hole, starting from horizon crossing of the over-dense region to the point of…
We numerically investigate the dynamics near black hole formation of solutions to the Einstein--Vlasov system in axisymmetry. Our results are obtained using a particle-in-cell and finite difference code based on the $(2+1)+1$ formulation of…
Evolution of inhomogeneities in the axion field around the QCD epoch is studied numerically, including for the first time important non-linear effects. It is found that perturbations on scales corresponding to causally disconnected regions…
We present results of a systematic study of failing core-collapse supernovae and the formation of stellar-mass black holes (BHs). Using our open-source general-relativistic 1.5D code GR1D equipped with a three-species neutrino…
We investigate the collapse of differentially rotating supermassive stars (SMSs) by means of 3+1 hydrodynamic simulations in general relativity. We particularly focus on the onset of collapse to understand the final outcome of collapsing…
We explore a possible scenario of the explosion as a result of core collapses of rotating massive stars that leave a black hole by performing a radiation-viscous-hydrodynamics simulation in numerical relativity. We take moderately and…
In high metallicity environments the mass that black holes (BHs) can reach just after core-collapse widely depends on how much mass their progenitor stars lose via winds. On one hand new theoretical and observational insights suggest that…
On the basis of a large collection of detailed 3D core-collapse supernova simulations carried to late times, we identify four channels of stellar mass black hole formation. Our examples for Channel 1 involve the formation of lower-gap and…
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 study the impact of stellar cooling due to light axion emission on the formation and evolution of black hole binaries, via stable mass transfer and the common envelope scenario. We find that in the presence of light axion emission, no…
We analyze the early growth stage of direct-collapse black holes (DCBHs) with $\sim 10^{5} \ \rm M_\odot$, which are formed by collapse of supermassive stars in atomic-cooling halos at $z \gtrsim 10$. A nuclear accretion disk around a…
The particle that makes up the dark matter of the universe could be an axion or axion-like particle. A collection of axions can condense into a bound Bose-Einstein condensate called an axion star. It is possible that a significant fraction…
In a certain class of scalar-Gauss-Bonnet gravity, the black holes and the neutron stars can undergo spontaneous scalarization -- a strong gravity phase transition triggered by a tachyonic instability due to the nonminimal coupling between…
We investigate the impact of stellar rotation on the formation of black holes (BHs), by means of our population-synthesis code SEVN. Rotation affects the mass function of BHs in several ways. In massive metal-poor stars, fast rotation…
We present a numerical code designed to study astrophysical phenomena involving dynamical spacetimes containing black holes in the presence of relativistic hydrodynamic matter. We present evolutions of the collapse of a fluid star from the…
We investigate the possibility of the existence of a classical version of Hawking radiation - solutions to classical field equations that consist solely of outgoing waves, in the spacetime of a collapsing black hole. The non-static nature…
The gravitational collapse of a spherically symmetric star, made of a dust fluid, $\rho_{DM}$, in a background of dark energy, $p = w\rho,\; (w < -1/3)$, is studied. It is found that when only dark energy is present, black holes are {\em…
Injecting 1-13.6 eV photons into the early universe can suppress the molecular hydrogen abundance and alter the star formation history dramatically enough to produce direct collapse black holes. These, in turn, could explain the recently…
The anomalous orbits of Trans-Neptunian Objects (TNOs) can be explained by the Planet 9 hypothesis. We propose that the Planet 9 can be an axion star. Axion stars are gravitational bound clusters condensed by QCD axions or axion-like…