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Related papers: Bondi Flow from Various Perspectives

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We investigate the Michel-type accretion onto a static spherically symmetric black hole. Using a Hamiltonian dynamical approach, we show that the standard method employed for tackling the accretion problem has masked some properties of the…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Ayyesha K. Ahmed , Mustapha Azreg-Aïnou , Mir Faizal , Mubasher Jamil

The present work addresses an axisymmetrically accreting black hole system from three perspectives: the astrophysical, the dynamical systems, and the emergent gravity standpoint. Steady-state equations governing low angular momentum axially…

High Energy Astrophysical Phenomena · Physics 2026-05-07 Kalyanbrata Pal , Souvik Ghose , Ripon Sk , Arpan Krishna Mitra , Tapas K. Das

The stationary hydrodynamic equations for the transonic accretion disks and flows around rotating black holes are presented by using the Kerr-Schild coordinate where there is no coordinate singularity at the event horizon. We use two types…

Astrophysics · Physics 2015-05-13 Rohta Takahashi

Classical black hole analogues (alternatively, the analogue systems) are fluid dynamical analogue of general relativistic black holes. Such analogue effects may be observed when acoustic perturbations (sound waves) propagate through a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Tapas Kumar Das

As of now, all analogue gravity models available in the literature deal with the emergence of an acoustic geometry through linear perturbations of transonic fluids only. It has never been investigated whether the analogue gravity phenomena…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Karan Fernandes , Susovan Maity , Tapas K. Das

We study viscous transonic accretion flows in vertical equilibrium in Kerr geometry. We employ the pseudo-Kerr formalism which accurately describes transonic flows around Kerr black holes and is applicable for modelling observational data.…

High Energy Astrophysical Phenomena · Physics 2024-10-01 Abhrajit Bhattacharjee , Sandip K. Chakrabarti

The formation of massive black holes and their coevolution with host galaxies are pivotal areas of modern astrophysics. Spherical accretion onto a central point mass serves as a foundational framework in cosmological simulations,…

High Energy Astrophysical Phenomena · Physics 2025-09-04 Razieh Ranjbar , Héctor R. Olivares-Sánchez , Shahram Abbassi

Low-angular-momentum, axisymmetric, inviscid accretion flows onto a black hole have been studied using the vertical equilibrium disc model, considering multiple pseudo-Schwarzschild potentials and two thermodynamic equations of state. A…

High Energy Astrophysical Phenomena · Physics 2026-05-13 Ripon Sk , Sangita Chatterjee , Sankhasubhra Nag

For general relativistic, inviscid, axisymmetric flow around Kerr black hole one may choose different flow thickness. The stationary flow equations can be solved using methods of dynamical system to get transonic accretion flows , i.e, flow…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Susovan Maity , Md Arif Shaikh , Pratik Tarafdar , Tapas K. Das

Transonic accretion onto astrophysical objects is a unique example of analogue black hole realized in nature. In the framework of acoustic geometry we study axially symmetric accretion and wind of a rotating astrophysical black hole or of a…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Hrvoje Abraham , Neven Bilic , Tapas K. Das

Analogue gravity models describe linear fluctuations of fluids as a massless scalar field propagating on stationary acoustic spacetimes constructed from the background flow. In this paper, we establish that this paradigm generalizes to…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Karan Fernandes , Susovan Maity , Tapas K. Das

An accretion flow around a black hole has a saddle type sonic point just outside the event horizon to guarantee that the flow enters the black hole supersonically. This feature exclusively present in strong gravity limit makes its marks in…

High Energy Astrophysical Phenomena · Physics 2016-04-21 Sandip K. Chakrabarti

In this paper I study stationary, spherically symmetric accretion of fluids onto a charged black hole in the presence of the cosmological constant. For some isothermal equations of state it is possible to obtain analytic solutions. In the…

General Relativity and Quantum Cosmology · Physics 2015-11-10 Filip Ficek

This study deals with astrophysical accretion onto the charged black hole solution, which is sourced by the dilation, spin, and shear charge of matter in metric affine gravity. The metric affine gravity defines the link between torsion and…

General Relativity and Quantum Cosmology · Physics 2023-12-29 G. Mustafa , A. Ditta , Faisal Javed , S. K. Maurya , Himanshu Chaudhary , Farruh Atamurotov

We linearly perturb advective isothermal transonic accretion onto rotating astrophysical black holes to study the emergence of the relativistic acoustic spacetime and to investigate how the salient features of such spacetime get influenced…

General Relativity and Quantum Cosmology · Physics 2018-02-05 Md Arif Shaikh

Low angular momentum, general relativistic, axially symmetric accretion of hydrodynamic fluid onto Schwarzschild black holes may undergo more than one critical transition. To obtain the stationary integral solutions corresponding to such…

High Energy Astrophysical Phenomena · Physics 2022-04-25 Arpan Krishna Mitra , Aishee Chakraborty , Pratik Tarafdar , Tapas Kumar Das

We investigate the accretion process for different spherically symmetric space-time geometries for a static fluid. We analyse this procedure using the most general black hole metric ansatz. After that, we examine the accretion process for…

General Relativity and Quantum Cosmology · Physics 2015-10-30 Sebastian Bahamonde , Mubasher Jamil

Spherically symmetric transonic accretion of a fractal medium has been studied in both the stationary and the dynamic regimes. The stationary transonic solution is greatly sensitive to infinitesimal deviations in the outer boundary…

Astrophysics · Physics 2007-08-30 Nirupam Roy , Arnab K. Ray

The stationary spherically symmetric accretion flow in the Schwarzschild metric has been set up as an autonomous first-order dynamical system, and it has been studied completely analytically. Of the three possible critical points in the…

Astrophysics · Physics 2008-11-26 Ipsita Mandal , Arnab K. Ray , Tapas Kumar Das

In astrophysics, accretion is the process by which a massive object acquires matter. The infall leads to the extraction of gravitational energy. Accretion onto dark compact objects such as black holes, neutron stars, and white dwarfs is a…

General Relativity and Quantum Cosmology · Physics 2024-12-19 Kourosh Nozari , Sara Saghafi , Mohammad Hassani