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Related papers: Entropy of Isolated Horizons revisited

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We give an account of the state of the art about black hole entropy in Loop Quantum Gravity. This chapter contains a historical summary and explains how black hole entropy is described by relying on the concept of isolated horizon, with an…

General Relativity and Quantum Cosmology · Physics 2022-12-29 J. Fernando Barbero G. , Daniele Pranzetti

A general analysis for characterizing and classifying `isolated horizons' is presented in terms of null tetrads and spin coefficients. The freely specifiable spin coefficients corresponding to isolated horizons are identified and specific…

General Relativity and Quantum Cosmology · Physics 2008-11-26 G. Date

We describe the quantum theory of isolated horizons with electromagnetic or non-Abelian gauge charges in a setting in which both gauge and gravitational field are quantized. We consider the distorted case, and its spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2018-05-02 Konstantin Eder , Hanno Sahlmann

We present a proposal for black hole microstate counting in Loop Quantum Gravity (LQG) for rotating (type~II) isolated horizons. The key obstacle in extending the standard nonrotating entropy derivation arises from the $\theta$-dependent…

General Relativity and Quantum Cosmology · Physics 2026-03-23 Pritam Nanda

The entropy of apparent horizons is derived using coherent states or semiclassical states in quantum gravity. The leading term is proportional to area for large horizons, and the correction terms differ according to the details of the graph…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Arundhati Dasgupta

Recently, many geometric aspects of $\mathcal{N}$-extended AdS supergravity in chiral variables have been encountered and clarified. In particular, if the theory is supposed to be invariant under SUSY transformations also on boundaries, the…

General Relativity and Quantum Cosmology · Physics 2022-07-20 Konstantin Eder , Hanno Sahlmann

We construct condensate states encoding the continuum spherically symmetric quantum geometry of an horizon in full quantum gravity, i.e. without any classical symmetry reduction, in the group field theory formalism. Tracing over the bulk…

General Relativity and Quantum Cosmology · Physics 2016-05-27 Daniele Oriti , Daniele Pranzetti , Lorenzo Sindoni

It is shown in this paper that the symplectic form for the system consisting of $D$-dimensional bulk Palatini gravity and SO$(1,1)$ BF theory on an isolated horizon as a boundary just contains the bulk term. An alternative quantization…

General Relativity and Quantum Cosmology · Physics 2016-08-17 Chao-Guang Huang , Jingbo Wang

The notion of Isolated Horizons has played an important role in gravitational physics, being useful from the characterization of the endpoint of black hole mergers to (quantum) black hole entropy. In particular, the definition of {\it…

General Relativity and Quantum Cosmology · Physics 2022-12-28 Alejandro Corichi , Juan D Reyes , Tatjana Vukašinac

We construct a SU(2) connection formulation of Kerr isolated horizons. As in the non-rotating case, the model is based on a SU(2) Chern-Simons theory describing the degrees of freedom on the horizon. The presence of a non-vanishing angular…

General Relativity and Quantum Cosmology · Physics 2012-12-21 Ernesto Frodden , Alejandro Perez , Daniele Pranzetti , Christian Roeken

To ask a question about a black hole in quantum gravity, one must restrict initial or boundary data to ensure that a black hole is actually present. For two-dimensional dilaton gravity, and probably a much wider class of theories, I show…

High Energy Physics - Theory · Physics 2010-04-28 S. Carlip

Boundary conditions defining a generic isolated horizon are introduced. They generalize the notion available in the existing literature by allowing the horizon to have distortion and angular momentum. Space-times containing a black hole,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Abhay Ashtekar , Christopher Beetle , Olaf Dreyer , Stephen Fairhurst , Badri Krishnan , Jerzy Lewandowski , Jacek Wisniewski

The exact formula derived by us earlier for the entropy of a four dimensional non-rotating black hole within the quantum geometry formulation of the event horizon in terms of boundary states of a three dimensional Chern-Simons theory, is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Romesh K. Kaul , Parthasarathi Majumdar

Equilibrium states of black holes can be modelled by isolated horizons. If the intrinsic geometry is spherical, they are called type I while if it is axi-symmetric, they are called type II. The detailed theory of geometry of \emph{quantum}…

General Relativity and Quantum Cosmology · Physics 2010-11-05 Abhay Ashtekar , Jonathan Engle , Chris Van Den Broeck

In any space-time, it is possible to have a family of observers who have access to only part of the space-time manifold, because of the existence of a horizon. We demand that \emph{physical theories in a given coordinate system must be…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Padmanabhan , Apoorva Patel

Aspects of holography or dimensional reduction in gravitational physics are discussed with reference to black hole thermodynamics. Degrees of freedom living on Isolated Horizons (as a model for macroscopic, generic, eternal black hole…

General Relativity and Quantum Cosmology · Physics 2008-02-12 Parthasarathi Majumdar

In LQG, black hole horizons are described by 2+1 dimensional boundaries of a bulk 3+1 dimensional spacetime. The horizon is endowed with area by lines of gravitational flux which pierce the surface. As is well known, counting of the…

General Relativity and Quantum Cosmology · Physics 2012-08-17 Deepak Vaid

Local symmetries of a non-expanding horizon has been investigated in the 1st order formulation of gravity. When applied to a spherically symmetric isolated horizon only a U(1) subgroup of the Lorentz group survives as residual local…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Rudranil Basu , Ayan Chatterjee , Amit Ghosh

In this paper, the isolated horizons with rotation are considered. It is shown that the symplectic form is the same as that in the nonrotating case. As a result, the boundary degrees of freedom can be also described by an SO$(1,1)$ BF…

General Relativity and Quantum Cosmology · Physics 2016-07-06 Jingbo Wang , Chao-Guang Huang

We extend the quasilocal (metric-based) Hamiltonian formulation of general relativity so that it may be used to study regions of spacetime with null boundaries. In particular we use this generalized Brown-York formalism to study the physics…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Ivan S. Booth