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Related papers: Black hole state counting in loop quantum gravity

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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

We develop a unified quantum framework for subgraph counting in graphs. We encode a graph on $N$ vertices into a quantum state on $2\lceil \log_2 N \rceil$ working qubits and $2$ ancilla qubits using its adjacency list, with worst-case gate…

Quantum Physics · Physics 2026-04-22 Bibhas Adhikari

Loop quantum gravity is a mature theory. To proceed to explicit calculations in cosmology, it is necessary to make assumptions and simplifications based on the symmetries of the cosmological setting. Symmetry reduction is especially…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Aurélien Barrau , Boris Bolliet

A succinct summary is given of the problem of reconciling observation of black hole-like objects with quantum mechanics. If quantum black holes behave like subsystems, and also decay, their information must be transferred to their…

High Energy Physics - Theory · Physics 2020-07-01 Steven B. Giddings

A `black hole sector' of non-perturbative canonical quantum gravity is introduced. The quantum black hole degrees of freedom are shown to be described by a Chern-Simons field theory on the horizon. It is shown that the entropy of a large…

General Relativity and Quantum Cosmology · Physics 2009-10-30 A. Ashtekar , J. Baez , A. Corichi , K. Krasnov

We argue for black hole entropy in loop quantum gravity (LQG) by taking into account the interpretation that there is no other side of the horizon. This gives new values for the Barbero-Immirzi parameter which are fairly larger than those…

High Energy Physics - Theory · Physics 2008-11-26 Takashi Tamaki

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 as well,…

General Relativity and Quantum Cosmology · Physics 2009-11-11 S. Carlip

We use the combinatorial and number-theoretical methods developed in previous work by the authors to study black hole entropy in the new proposal put forward by Engle, Noui and Perez. Specifically we give the generating functions relevant…

General Relativity and Quantum Cosmology · Physics 2009-10-07 Ivan Agullo , J. Fernando Barbero G. , Enrique F. Borja , Jacobo Diaz-Polo , Eduardo J. S. Villaseñor

One central question in quantum gravity is to understand how and why predictions from semiclassical gravity can break down in regimes with low spacetime curvature. One diagnostic of such a breakdown is that states which are orthonormal at…

High Energy Physics - Theory · Physics 2026-03-30 John Preskill , Mykhaylo Usatyuk , Shreya Vardhan

Since the early days of search for a quantum theory of gravity the attempts have been mostly concentrated on the quantization of an otherwise classical system. The two most contentious candidate theories of gravity, sting theory and quantum…

General Relativity and Quantum Cosmology · Physics 2009-07-24 Houri Ziaeepour

It is not known what the limitations are on using quantum computation to speed up classical computation. An example would be the power to speed up PSPACE-complete computations. It is also not known what the limitations are on the duration…

High Energy Physics - Theory · Physics 2018-02-08 Leonard Susskind

Quantum considerations have led many theorists to believe that classical black hole physics is modified not just deep inside black holes but at {\it horizon scales}, or even further outward. The near-horizon regime has just begun to be…

General Relativity and Quantum Cosmology · Physics 2016-11-14 Steven B. Giddings

Simple considerations about the fractal characteristic of the quantum-mechanical path give us the opportunity to derive the quantum black hole entropy in connection with the concept of fractal statistics. We show the geometrical origin of…

High Energy Physics - Theory · Physics 2007-05-23 Wellington da Cruz

I review the present theoretical attempts to understand the quantum properties of spacetime. In particular, I illustrate the main achievements and the main difficulties in: string theory, loop quantum gravity, discrete quantum gravity…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Carlo Rovelli

We review the approach to quantum gravity based on supersymmetry, strings, and holography. This includes a survey of black holes in higher-dimensions, supersymmetry and supergravity, as well as string theory, black hole microstates, and the…

General Relativity and Quantum Cosmology · Physics 2014-05-29 Henriette Elvang , Gary T. Horowitz

We study $\mathcal{N}=4$ SYM at non-integer number of colours. By varying $N$ we can continuously follow states all the way from $N=\infty$ where integrability reigns to finite $N$ where quantum gravity effects dominate. As an application…

High Energy Physics - Theory · Physics 2023-09-15 Kasia Budzik , Harish Murali , Pedro Vieira

The entropy S of any mass M can be interpreted as a linear relation with mass, S of order kM/mg an extensive property with mg the mass of the quantum of gravity. One can extend this relation to black holes and then we get a different…

Astrophysics · Physics 2007-05-23 Antonio Alfonso-Faus

We discuss the meaning of geometrical constructions associated to loop quantum gravity states on a graph. In particular, we discuss the "twisted geometries" and derive a simple relation between these and Regge geometries.

General Relativity and Quantum Cosmology · Physics 2014-11-21 Carlo Rovelli , Simone Speziale

Understanding how to prepare and count black hole micro-states by using the gravitational path integral is one of the most important problems in quantum gravity. Nevertheless, a state-by-state count of black hole microstates is difficult…

High Energy Physics - Theory · Physics 2024-07-08 Jan Boruch , Luca V. Iliesiu , Cynthia Yan

In general relativity, the fields on a black hole horizon are obtained from those in the bulk by pullback and restriction. Similarly, in quantum gravity, the quantized horizon degrees of freedom should result from restricting, or…

General Relativity and Quantum Cosmology · Physics 2011-09-13 Hanno Sahlmann