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Related papers: Black Holes without Event Horizons

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A general definition of a black hole is given, and general `laws of black-hole dynamics' derived. The definition involves something similar to an apparent horizon, a trapping horizon, defined as a hypersurface foliated by marginal surfaces…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Sean A. Hayward

We have known for more than thirty years that black holes behave as thermodynamic systems, radiating as black bodies with characteristic temperatures and entropies. This behavior is not only interesting in its own right; it could also,…

General Relativity and Quantum Cosmology · Physics 2009-01-28 Steven Carlip

We first show that the intrinsic, geometrical structure of a dynamical horizon is unique. A number of physically interesting constraints are then established on the location of trapped and marginally trapped surfaces in the vicinity of any…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Abhay Ashtekar , Gregory J. Galloway

We model a black hole spacetime as a causal set and count, with a certain definition, the number of causal links crossing the horizon in proximity to a spacelike or null hypersurface $\Sigma$. We find that this number is proportional to the…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Djamel Dou , Rafael D. Sorkin

Several properties of canonical quantum gravity modify space-time structures, sometimes to the degree that no effective line elements exist to describe the geometry. An analysis of solutions, for instance in the context of black holes, then…

General Relativity and Quantum Cosmology · Physics 2011-11-04 Martin Bojowald , George M. Paily , Juan D. Reyes , Rakesh Tibrewala

We analyze the thermodynamical properties of black holes in a modified theory of gravity, which was initially proposed to obtain correct dynamics of galaxies and galaxy clusters without dark matter. The thermodynamics of non-rotating and…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Jonas R. Mureika , John W. Moffat , Mir Faizal

In this work some proposals for black hole entropy interpretation are exposed and investigated. In particular I will firstly consider the so called ``entanglement entropy" interpretation, in the framework of the brick wall model, and the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Liberati

This thesis explores two avenues into understanding the physics of black holes and horizons beyond general relativity, via analogue models and Lorentz violating theories. Analogue spacetimes have wildly different dynamics to general…

General Relativity and Quantum Cosmology · Physics 2016-11-02 Bethan Cropp

Hawking radiation is nowadays being understood as tunnelling through black hole horizons. Here, the extension of the Hamilton-Jacobi approach to tunnelling for non-rotating and rotating black holes in different non-singular coordinate…

High Energy Physics - Theory · Physics 2010-04-29 Bhramar Chatterjee , A. Ghosh , P. Mitra

We discuss the validity of the Thakurta metric to describe cosmological black holes by analysing the nature of its horizon. By adopting the preferred foliation of the Thakurta spacetime associated with the Kodama time, we demonstrate that…

General Relativity and Quantum Cosmology · Physics 2022-05-04 Archil Kobakhidze , Zachary S. C. Picker

We show that the entropy of any black object in any dimension can be understood as the entropy of a highly excited string on the stretched horizon. The string has a gravitationally renormalized tension due to the large redshift near the…

High Energy Physics - Theory · Physics 2010-02-03 Edi Halyo

The thermodynamic properties of black holes -- temperature, entropy and radiation rates -- are usually associated with the presence of a horizon. We argue that any Extremely Compact Object (ECO) must have the {\it same} thermodynamic…

High Energy Physics - Theory · Physics 2023-11-06 Samir D. Mathur , Madhur Mehta

Hawking radiation elucidates black holes as quantum thermodynamic systems, thereby establishing a conceptual bridge between general relativity and quantum mechanics through particle emission phenomena. While conventional theoretical…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Cheng Hu , Xiao-Xiong Zeng

A brief overview of the discovery that macroscopic black holes are thermodynamical systems is presented. They satisfy the laws of thermodynamics and are associated with a temperature and an entropy equal to one quarter of their horizon area…

General Relativity and Quantum Cosmology · Physics 2023-10-31 Alejandro Perez

We study the intriguing analogy between gravitational dynamics of the horizon and thermodynamics for the case of nonstationary radiating spherically symmetric black holes both in four dimensions and higher dimensions. By defining all…

General Relativity and Quantum Cosmology · Physics 2014-11-11 Uma Papnoi , Megan Govender , Sushant G Ghosh

A different reason for the apparent weakness of the gravitational interaction is advanced, and its consequences for Hawking evaporation of a Schwarzschild black hole are investigated. Proceeding from some fundamental thermodynamic…

High Energy Physics - Theory · Physics 2009-05-12 D. G. Coyne , D. C. Cheng

We explore the thermodynamics and geothermodynamics of black holes with Barrow entropy in a brane-world scenario, where the horizon geometry of the black hole is regarded as a fractal structure. Our analysis reveals the behavior of heat…

General Relativity and Quantum Cosmology · Physics 2026-04-02 Usman Zafar , Abdul Jawad , Kazuharu Bamba , Mohammad Ali S. Afshar , Mohammad Reza Alipour , Saeed Noori Gashti , Jafar Sadeghi

The event horizon of black holes and white holes can be achieved in the context of analogue gravity. It was proven for a sonic case that if these two horizons are close to each other their dynamics resemble a laser, a black hole laser,…

General Relativity and Quantum Cosmology · Physics 2017-04-05 José L. Gaona Reyes , David Bermudez

Because of colour confinement, the physical vacuum forms an event horizon for quarks and gluons; this can be crossed only by quantum tunneling, i.e., through the QCD counterpart of Hawking radiation by black holes. Since such radiation…

High Energy Physics - Phenomenology · Physics 2017-08-23 P. Castorina

For a rotating black hole to be nonsingular, it means that there are no spacetime singularities at its center. The destruction of the event horizon of such a rotating black hole is not constrained by the weak cosmic censorship conjecture,…

General Relativity and Quantum Cosmology · Physics 2023-10-26 Lai Zhao , Zhaoyi Xu
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