We consider a simple Newtonian model of a steady accretion disk around a black hole. The model is based on height-integrated hydrodynamic equations, α-viscosity, and a pseudo-Newtonian potential that results in an innermost stable circular orbit (ISCO) that closely approximates the one predicted by GR. We find that the hydrodynamic models exhibit increasing deviations from the standard disk mod...

Rohitvarma Basavaraju∗ and David A. Lowe† Department of Physics, Brown University, Providence, RI 02912, USA (Dated: November 8, 2016) Abstract We consider the possibility of mining black holes in the 1+1-dimensional dilaton gravity model of Russo, Susskind and Thorlacius. The model correctly incorporates Hawking radiation and backreaction in a semiclassical expansion in 1/N , where N is the nu...

In models with large extra dimensions, particle collisions with center-of-mass energy larger than the fundamental gravitational scale can generate nonperturbative gravitational objects. Since cosmic rays have been observed with energies above 108 TeV, gravitational effects in the TeV energy range can, in principle, be observed by ultrahigh energy cosmic ray detectors. We consider the interactio...

We calculate eclipsing light curves for accretion flows around a rotating black hole taking into account the atmospheric effects of the companion star. In the cases of no atmospheric effects, the light curves contain the information of the black hole spin because most of X-ray photons around 1 keV usually comes from the blue-shifted part of the accretion flow near the black-hole shadow and the ...

Relation models have treated multi-holed regions relations either the same as hole-free regions relations, loosing this way the peculiarities of the holed topology, or with methods dependent on the number of holes. This paper discusses a model of relations between a hole-free and a multi-holed region that departs from past approaches by using the frequencies of the relations in which the holes ...

We propose a new model for the disk-jet connection in black hole x-ray transients and active galactic nuclei. In our model, the inner part of the accretion disk around the central black hole switches between two states. In one state, the accretion energy is dissipated locally (some within the disk, some within a corona) to produce the observed disk luminosity. In the second state, the accretion...

Studies of one-and two-hole states in the 2D t-J model via series expansions Abstract We study one and two hole properties of the t-J model at half-filling on the square lattice using series expansion methods at T = 0. The dispersion curve for one hole excitations is calculated and found to be qualitatively similar to that obtained by other methods, but the bandwidth for small t/J is some 20% l...

We present the results of a systematic study of the formation and evolution of binaries containing black holes and normal-star companions with a wide range of masses. We first reexamine the standard formation scenario for close black-hole binaries, where the progenitor system, a binary with at least one massive component, experienced a common-envelope phase and where the spiral-in of the compan...

We construct an exact conformal field theory as an SL(2, R) × SU(2)/U(1)2 gauged WZW model, which describes a black hole in four dimensions. Another exact solution, describing a black membrane in four dimensions (in the sense that the event horizon is an infinite plane) is found as an SL(2, R)×U(1)2/U(1) gauged WZW model. Both the black hole and the black membrane carry axionic charge. Finally,...