Related papers: Gravitational Encounters and the Evolution of Gala…
We consider the emission of gravitational waves in the two proposed models for the collapse of a massive star to a black hole: the prompt collapse, in which nearly all the star collapses to a black hole in a dynamical time scale, and the…
The dynamics of galactic nuclei can be affected by several mechanisms. Among these are stellar evolution, stellar collisions, mass segregation, and tidal disruptions of stars due to the central black hole. In this presentation I will…
One of the problems for the cyclic Universe will be its compatibility with a vast population of indestructible black holes that accumulate from cycle to cycle. The article considers a simple iterative model of the evolution of black holes…
Recent gravitational wave observations include possible detections of black hole - neutron star binary mergers. As with binary black hole mergers, numerical simulations help characterize the sources. For binary systems with neutron star…
The density of stars in galactic bulges is often observed to be flat or slowly rising inside the influence radius of the supermassive black hole (SMBH). Attributing the dynamical friction force to stars moving more slowly than the test…
We elucidate the feature of gravitational waves (GWs) from binary neutron star merger collapsing to a black hole by general relativistic simulation. We show that GW spectrum imprints the coalescence dynamics, formation process of disk,…
We consider the cosmological model in which a part of the Universe \Omega_h\sim 10^-5 is in the form of primordial black holes with mass \sim 10^5M_\odot. These primordial black holes would be centers for growing protogalaxies which…
The central regions of galaxies show the presence of massive black holes and/or dense stellar systems. The question about their modes of formation is still under debate. A likely explanation of the formation of the central dense stellar…
The cosmological evolution of the binary black hole (BH) merger rate and the energy density of the gravitational-wave (GW) background are investigated. To evaluate the redshift dependence of the BH formation rate, BHs are assumed to…
Understanding the predictions of general relativity for the dynamical interactions of two black holes has been a long-standing unsolved problem in theoretical physics. Black-hole mergers are monumental astrophysical events, releasing…
Black holes, dark energy, and the Higgs field are all currently established, exciting, and mysterious, each in its own way. Cosmological data show that dark energy may evolve with time. The electroweak phase transition during stellar…
The dark matter halo profile in the inner Galaxy is very uncertain. Yet its radial dependence toward the Galactic Center is of crucial importance for the determination of the gamma-ray and radio fluxes originating from dark matter…
Black hole (BH) binary mergers formed through dynamical interactions in dense star clusters are believed to be one of the main sources of gravitational waves for Advanced LIGO and Virgo. Here we present a fast numerical method for…
The particles of a dark matter due to gravitational interaction deviate from straight trajectories in the vicinity of a massive body. This causes their density to become inhomogeneous. The developed density contrast causes a gravitation…
We investigated the evolution of the black hole binary formed by the merging of two galaxies each containing a central massive black hole. Our main goal here is to determine if the black hole binary can merge through the hardening by…
A generic black hole merger occurs through a restructuring of creases (sharp edges) on the event horizon. This process is studied for a black hole merger in the limit of infinite mass ratio, for which constructing the event horizon reduces…
The discovery of cosmic acceleration has presented a unique challenge for cosmologists. As observational cosmology forges ahead, theorists have struggled to make sense of a standard model that requires extreme fine tuning. This challenge is…
Hydrodynamic simulations of the merger of stellar mass black hole - neutron star binaries (BH/NS) are compared with mergers of binary neutron stars (NS/NS). The simulations are Newtonian, but take into account the emission and backreaction…
The semi-analytic theory of tidal shocks proves to be a powerful tool to study tidal interactions of star clusters and satellite galaxies with their massive hosts. New models of the globular cluster evolution employ a combination of…
We study the threshold of gravitational collapse in spherically symmetric spacetimes governed by the Einstein-Maxwell-Vlasov equations. We numerically construct solutions describing a collapsing distribution of charged matter that either…