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Related papers: Cloud of strings in f(R) gravity

200 papers

In this paper, we investigate the thermodynamic properties of spherically symmetric, static black hole solutions within the framework of Conformal Killing Gravity (CKG). This is a modified theory of gravity that retains all solutions of…

General Relativity and Quantum Cosmology · Physics 2025-08-19 S. Ghaffari , G. G. Luciano

In the context of the black hole/string transition, it is useful to produce Euclidean string backgrounds representing hot and self-gravitating strings. We utilise analytical and numerical methods to find a smooth, stationary rotating…

High Energy Physics - Theory · Physics 2024-04-01 Jorge E. Santos , Yoav Zigdon

In the string theory, the fundamental blocks of nature are not particles but one-dimensional strings. Therefore, a generalization of this idea is to think of it as a cloud of strings. Rodrigues et al. embedded the black bounces spacetime…

General Relativity and Quantum Cosmology · Physics 2023-03-17 Yi Yang , Dong Liu , Zhaoyi Xu , Zheng-Wen Long

We investigate the thermodynamic properties of charged anti-de Sitter black holes surrounded by a cloud of strings in bumblebee gravity. In this framework, the cloud-of-strings parameter $\alpha$ and the Lorentz-violating parameter $\ell$…

General Relativity and Quantum Cosmology · Physics 2026-03-20 Faizuddin Ahmed , Edilberto O. Silva

Lovelock theory is a natural extension of the Einstein theory of general relativity to higher dimensions in which the first and second orders correspond, respectively, to general relativity and Einstein-Gauss-Bonnet gravity. We present…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Sushant G. Ghosh , Uma Papnoi , Sunil D. Maharaj

We have argued previously that the infinitely many gauge symmetries of string theory provide an infinite set of conserved (gauge) quantum numbers ($W$-hair) which characterise black hole states and maintain quantum coherence. Here we study…

High Energy Physics - Theory · Physics 2009-09-11 John Ellis , N. E. Mavromatos , D. V. Nanopoulos

We review some recent results obtained for black holes using effective field theory methods applied to quantum gravity, in particular the unique effective action. Black holes are complex thermodynamical objects that not only have a…

High Energy Physics - Theory · Physics 2022-02-08 Xavier Calmet , Folkert Kuipers

We derive the wave equation for a minimally coupled scalar field in the background of a general rotating five-dimensional black hole. It is written in a form that involves two types of thermodynamic variables, defined at the inner and outer…

High Energy Physics - Theory · Physics 2009-09-17 Mirjam Cvetic , Finn Larsen

We point out that the recent conjecture relating large N gauge theories to string theory in anti-de Sitter spaces offers a resolution in principle of many problems in black hole physics. This is because the gauge theory also describes…

High Energy Physics - Theory · Physics 2016-09-06 Gary T. Horowitz , Simon F. Ross

Using thermal quantization of geodesics confined under horizons and reasonable conjecture on massless modes, we evaluate quantum spectrum of Kerr black hole masses compatible with superstring symmetries.

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. V. Kiselev

In this work, we re-assess a class of black hole solutions in a global monopole spacetime in the framework of an $f(R)$-gravity model. Our main line of investigation consists in considering a region close enough to the black hole, but such…

Two dimensional classical string theory is solved in any curved spacetime. The complete spacetime required to describe the classical string motions turns out to be larger than the global space required by complete particle geodesics. The…

High Energy Physics - Theory · Physics 2008-02-03 Itzhak Bars

We find all the classical solutions (minimal surfaces) of open or closed strings in {\it any} two dimensional curved spacetime. As examples we consider the SL(2,R)/R two dimensional black hole, and any 4D black hole in the Schwarzschild…

High Energy Physics - Theory · Physics 2009-10-28 Itzhak Bars , Jürgen Schulze

Charged black holes, both spherically symmetric and rotating, in the low energy limit of string theory (Einstein-Maxwell-dilaton theory) are compared to analogous geometries in pure general relativity. We describe various physical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 R. Casadio , B. Harms

We establish a framework to construct spherically symmetric and static solutions in $f(R)$ gravity coupled with nonlinear electromagnetic fields. We present two new specific solutions and discuss the energy conditions. We calculate some…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Yongben Shi , Rong-Jia Yang

An effective string theory in physically relevant cosmological and black hole space times is reviewed. Explicit computations of the quantum string entropy, partition function and quantum string emission by black holes (Schwarzschild,…

High Energy Physics - Theory · Physics 2008-11-26 Marina Ramon Medrano , Norma G. Sanchez

We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work JHEP 1403 (2014) 086. The relevance of long strings to one-loop black hole…

High Energy Physics - Theory · Physics 2015-07-02 Thomas G. Mertens , Henri Verschelde , Valentin I. Zakharov

We study some features of static and spherically symmetric solutions (SSS) with a horizon in $f(R)$ theories of gravitation by means of a near-horizon analysis. A necessary condition for an $f(R)$ theory to have this type of solution is…

General Relativity and Quantum Cosmology · Physics 2013-05-29 Santiago Esteban Perez Bergliaffa , Yves Eduardo Chifarelli de Oliveira Nunes

In this paper, we investigate the thermodynamic properties of the RN-AdS black hole with cloud of strings and quintessence in rainbow gravity with the stationary (ST) orthonormal frame and the free-fall (FF) orthonormal frame. After the SF…

General Relativity and Quantum Cosmology · Physics 2022-05-06 Siyuan Hui , Benrong Mu , Yuzhou Tao , Jun Tao

In this paper we study the first law of thermodynamics for the (2+1) dimensional charged BTZ black hole considering a pair of thermodinamical systems constructed with the two horizons of this solution. We show that these two systems are…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Alexis Larranaga