相关论文: Transonic Black Hole Accretion as Analogue System
The stationary hydrodynamic equations for transonic viscous accretion discs in Kerr geometry are derived. The consistent formulation is given for the viscous angular momentum transport and the boundary conditions on the horizon of a central…
In this brief review, we will address acoustic black holes arising from quantum field theory in the Lorentz-violating and non-commutative background. Thus, we consider canonical acoustic black holes with effective metrics for the purpose of…
We introduce a novel formalism to investigate the role of the spin angular momentum of astrophysical black holes in influencing the behaviour of low angular momentum general relativistic accretion. We propose a metric independent analysis…
Classically, black holes are compact objects with perfect semi-permeable horizons: Anything may enter, nothing may leave. We consider an axiomatic approach that applies to any black hole type, including arbitrarily near-extremal black…
The model is built in which the main global properties of classical and quasi-classical black holes become local. These are the event horizon, "no-hair", temperature and entropy. Our construction is based on the features of a quantum…
Cooling flows in galaxy clusters and isolated elliptical galaxies are a source of mass for fueling accretion onto a central supermassive black hole. We calculate the dynamics of accreting matter in the combined gravitational potential of a…
In the present work, accretion onto a static spherically symmetric black hole in the hybrid metric-Palatini gravity is considered. The Novikov-Thorne model for a relativistic thin accretion disk is used. The energy flux, temperature…
The main aim of the present work is to demonstrate that the analogue gravity phenomena are not an artifact of linear perturbation, rather gravity-like effects emerge through the non linear higher order perturbation of transonic fluid as…
The microcanonical ensemble is the proper ensemble to describe black holes which are not in thermodynamic equilibrium, such as radiating black holes. This choice of ensemble eliminates the problems, e.g. negative specific heat and loss of…
We investigate the steady spherically symmetric accretion in the combined potential of a central black hole and a dark matter halo. For the halo, we consider a Hernquist and an NFW potential and calculate the critical points of the flow. We…
Black holes behave as thermodynamic systems, and a central task of any quantum theory of gravity is to explain these thermal properties. A statistical mechanical description of black hole entropy once seemed remote, but today we suffer an…
Recent experimental progresses in controlling classical and quantum fluids have made it possible to realize acoustic analogues of gravitational black holes, where a flowing fluid provides an effective spacetime on which sound waves…
The environment surrounding a black hole or black hole binaries is generally expected to play an important role in understanding various astrophysical phenomena around them. In this paper, we study relativistic, low angular momentum,…
Gravitational wave echoes from the black holes have been suggested as a crucial observable to probe the spacetime in the vicinity of the horizon. In particular, it was speculated that the echoes are closely connected with specific…
In the corpuscular picture of black hole there exists no geometric notion of horizon which, instead, only emerges in the semi-classical limit. Therefore, it is very natural to ask - what happens if we send a signal towards a corpuscular…
We study the back-reaction associated with Hawking evaporation of an acoustic canonical analogue black hole in a Bose-Einstein condensate. We show that the emission of Hawking radiation induces a local back-reaction on the condensate,…
In this work we suggest a simplified "quasi-classical" formalism of the Schwarzschild black hole thermodynamics. We define such small quantum system at Schwarzschild black hole horizon surface whose reduced Compton wavelength equals one…
Accretion onto black holes is one of the most efficient energy source in the Universe. Black hole accretion powers some of the most luminous objects in the universe, including quasars, active galactic nuclei, tidal disruption events,…
From the microscopic point of view, realistic black holes are time-dependent and the teleological concept of event horizon fails. At present, the apparent or the trapping horizon seem its best replacements in various areas of black hole…
The images of supermassive black holes surrounded by optically-thin, radiatively-inefficient accretion flows, like those observed with the Event Horizon Telescope, are characterized by a bright ring of emission surrounding the black-hole…