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Related papers: Accretion on High Derivative Asymptotically Safe B…

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Vacuum spherically symmetric loop quantum gravity in the midi-superspace approximation using inhomogeneous horizon-penetrating slices has been studied for a decade, and it has been noted that the singularity is eliminated. It is replaced by…

General Relativity and Quantum Cosmology · Physics 2024-02-20 Rodolfo Gambini , Javier Olmedo , Jorge Pullin

The paper studies axial gravitational perturbations of the Hayward black hole, a regular geometry that also arises as an effective solution in asymptotically safe gravity. By computing grey-body factors with the 6th-order WKB method and…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Zainab Malik

We investigate the dynamical structure of advective accretion flow around stationary as well as rotating black holes. For a suitable choice of input parameters, such as, accretion rate ($\dot {\cal M}$) and angular momentum ($\lambda$),…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Santabrata Das , Sandip K. Chakrabarti , Soumen Mondal

I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of…

High Energy Astrophysical Phenomena · Physics 2014-10-31 Mitchell C. Begelman

We derive the quantum effective action and the respective quantum equations of motion from multi-graviton correlation functions in asymptotically safe quantum gravity. The fully momentum-dependent couplings of three- and four-graviton…

High Energy Physics - Theory · Physics 2024-10-10 Jan M. Pawlowski , Jan Tränkle

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…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Ziri Younsi , Dimitrios Psaltis , Feryal Özel

We study numerically the axisymmetric relativistic Bondi-Hoyle accretion of a supersonic ideal gas onto a fixed Schwarzschild background space-time described with horizon penetrating coordinates. We verify that a nearly stationary shock…

High Energy Astrophysical Phenomena · Physics 2013-04-11 F. D. Lora-Clavijo , F. S. Guzman

Non-pertrubative quantum gravity formulated as a unitary four-dimensional theory suggests that certain amount of non-locality, such as infinite-derivative operators, can be present in the action, in both cases of Analytic Infinite…

High Energy Physics - Theory · Physics 2024-12-04 Alexey S. Koshelev , Chenxuan Li , Anna Tokareva

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

The hydrodynamic behaviour of perfect fluid orbiting around black holes in spherically symmetric spacetime for various alternative gravity theories has been investigated. For this purpose we have assumed an uniform distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-03-11 Sumanta Chakraborty

We consider the most general static spherically symmetric black hole metric. The accretion of the fluid flow around the Van der Waal's black hole is investigated and we calculate the fluid's four-velocity, the critical point and the speed…

General Relativity and Quantum Cosmology · Physics 2019-03-27 Sandip Dutta , Ritabrata Biswas

The accretion of hot, dense matter which consists of heavy nuclei, free nucleons, degenerated electrons, photons and neutrinos is studied. The composition of free nucleons and their chemical potentials are provided through the equation of…

Astrophysics · Physics 2007-05-23 M. Yokosawa , S. Uematsu , J. Abe

We review aspects of the interplay of asymptotically safe gravity with matter, focusing on the potential predictive power of the quantum scale-symmetry underlying the asymptotically safe fixed point. We explain how an asymptotically safe…

High Energy Physics - Theory · Physics 2019-07-12 Astrid Eichhorn , Aaron Held

In this article we investigate the properties of the asymptotically Schwarzschild-like metric as an alternative to the Schwarzschild solution in General Relativity. While asymptotically flat and similar to Schwarzschild at large distances…

General Relativity and Quantum Cosmology · Physics 2025-11-18 K. K. Ernazarov

We present a class of exact analytic and static, spherically symmetric black hole solutions in the semi-classical Einstein equations with Weyl anomaly. The solutions have two branches, one is asymptotically flat and the other asymptotically…

High Energy Physics - Theory · Physics 2010-04-30 Rong-Gen Cai , Li-Ming Cao , Nobuyoshi Ohta

We discuss the emergent spectra from accreting black holes, considering in particular the case where the accretion is characterized by relativistic bulk motion. We suggest that such accretion is likely to occur in a wide variety of black…

Astrophysics · Physics 2009-10-30 Chris Shrader , Lev Titarchuk

In this paper, we obtain analytical approximate black hole solutions in the framework of $f(R)$ gravity and the absence of a cosmological constant. In this area, we apply the equations of motion of the theory to a spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2023-03-08 Seyed Naseh Sajadi , Ali Hajilou , Seyed Hossein Hendi

In this work we study static spherically symmetric solutions of effective field equations related to local and nonlocal higher-derivative gravity models, based on their associated effective delta sources. This procedure has been applied to…

General Relativity and Quantum Cosmology · Physics 2024-09-16 Tibério de Paula Netto , Breno L. Giacchini , Nicolò Burzillà , Leonardo Modesto

The recently proposed theory of "Asymptotically Free Mimetic Gravity" is extended to the general non-homogeneous, spatially non-flat case. We present a modified theory of gravity which is free of higher derivatives of the metric. In this…

High Energy Physics - Theory · Physics 2020-08-05 Ali H. Chamseddine , Viatcheslav Mukhanov , Tobias B. Russ

In this Letter, we examine the phantom energy accretion onto a Kehagias-Sfetsos black hole in Ho$\check{r}$ava Lifshitz gravity. To discuss the accretion process onto the black hole, the equations of phantom flow near the black hole have…

General Relativity and Quantum Cosmology · Physics 2014-03-11 G. Abbas
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