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Related papers: Counting the Apparent Horizon

200 papers

In this paper, we develop an effective quantum theory of black hole horizons using only the local horizon geometry. On the covariant phase space of the Holst action admitting Weak Isolated Horizon as an inner boundary, we construct…

General Relativity and Quantum Cosmology · Physics 2019-09-19 Ayan Chatterjee , Amit Ghosh

The quasi-local notion of an isolated horizon is employed to study the entropy of black holes without any particular symmetry in loop quantum gravity. The idea of characterizing the shape of a horizon by a sequence of local areas is…

General Relativity and Quantum Cosmology · Physics 2021-11-02 Shupeng Song , Haida Li , Yongge Ma , Cong Zhang

The entropy of a quantum-statistical system which is classically approximated by a general stationary eternal black hole is studied by means of a microcanonical functional integral. This approach opens the possibility of including…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Erik A. Martinez

The notions of temperature, entropy and `evaporation', usually associated with spacetimes with horizons, are analyzed using general approach and the following results, applicable to different spacetimes, are obtained at one go. (i) The…

General Relativity and Quantum Cosmology · Physics 2016-08-31 T. Padmanabhan

In transforming from Schwarzschild to Euclidean Rindler coordinates the Schwarzschild time transforms to a periodic angle. As is well-known, this allows one to introduce the Hawking temperature and is an origin of black hole thermodynamics.…

General Relativity and Quantum Cosmology · Physics 2009-09-01 Kostyantyn Ropotenko

In a remarkable numerical analysis of the spectrum of states for a spherically symmetric black hole in loop quantum gravity, Corichi, Diaz-Polo and Fernandez-Borja found that the entropy of the black hole horizon increases in what resembles…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hanno Sahlmann

The apparent shadow of a black hole provides one of the most direct probes of strong-field general relativity. While the shadow size in asymptotically flat spacetimes is well understood, the influence of cosmic expansion on its apparent…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Debarshi Mukherjee

It has been argued by several authors that the quantum mechanical spectrum of black hole horizon area must be discrete. This has been confirmed in different formalisms, using different approaches. Here we concentrate on two approaches, the…

High Energy Physics - Theory · Physics 2009-11-07 Saurya Das , P. Ramadevi , U. A. Yajnik

We show that the entropy of Schwarzschild black holes in any dimension can be described by a gas of free string bits at the stretched horizon. The number of string bits is equal to the black hole entropy and energy dependent. For an…

High Energy Physics - Theory · Physics 2007-05-23 Edi Halyo

The entropy for a black hole in a de Sitter space is approached within the framework of spacetime foam. A simple model, made by $N$ wormholes in a semiclassical approximation, is taken under examination to compute the entropy for such a…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Remo Garattini

In this paper, we successfully derive the Bekenstein-Hawking entropy for Schwarzschild black holes in various dimensions by using a non-trivial phase space. It is appealing to notice that the thermodynamics of a Schwarzschild black hole…

General Relativity and Quantum Cosmology · Physics 2020-05-05 Yong Xiao

When a classical black hole is perturbed, its relaxation is governed by a set of quasinormal modes with complex frequencies \omega= \omega_R+i\omega_I. We show that this behavior is the same as that of a collection of damped harmonic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Michele Maggiore

We show that the Wald Noether charge entropy is canonically conjugate to the opening angle at the horizon. Using this canonical relation we extend the Wheeler-DeWitt equation to a Schroedinger equation in the opening angle, following Carlip…

High Energy Physics - Theory · Physics 2015-06-04 Ram Brustein , Merav Hadad

We examine a possibility that, when a black hole is formed, the information on the collapsed star is stored as the entanglement entropy between the outside and the thin region (of the order of the Planck length) of the inside the horizon.…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Hiroaki Terashima

Quantum fluctuations of the spacetime metric induce an uncertainty in the horizon area of a black hole. Working in linearized quantum gravity, we derive the variance in the area of a four-dimensional Schwarzschild black hole from the…

High Energy Physics - Theory · Physics 2025-08-05 Maulik Parikh , Jude Pereira

We present an overall picture of the advances in the description of black hole physics from the perspective of loop quantum gravity. After an introduction that discusses the main conceptual issues we present some details about the classical…

General Relativity and Quantum Cosmology · Physics 2015-01-14 J. Fernando Barbero G. , Alejandro Perez

As is well known, near-horizon (equivalently high acceleration) observers in spherically symmetric black hole spacetimes have a particularly simple form of the quasi-local energy. Using this energy and indistinguishable area quanta…

General Relativity and Quantum Cosmology · Physics 2026-03-03 Ryley McGovern , Seth Major , Trevor Scheuing , Thomas Takis

The statistical entropy of a Schwarzschild black string in five dimensions is obtained by counting the black string states which form a representation of the near-horizon conformal symmetry with a central charge. The statistical entropy of…

High Energy Physics - Theory · Physics 2009-10-31 Saurya Das , Amit Ghosh , P. Mitra

The Bekenstein-Hawking formula relates the black hole entropy and horizon area. Semiclassical entropy computations have relied on an action principle that fixes a gauge dependent and classically unobservable boundary three-geometry and…

High Energy Physics - Theory · Physics 2018-11-28 Thomas C. Bachlechner

We investigate the consequences for the black hole area of introducing fractal structure for the horizon geometry. We create a three-dimensional spherical analogue of a 'Koch Snowflake' using a infinite diminishing hierarchy of touching…

General Relativity and Quantum Cosmology · Physics 2020-08-06 John D. Barrow