English
Related papers

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

200 papers

We derive and analyze a Schwarzschild-like Anti-de Sitter (AdS) black hole (BH) obtained as a static, spherically symmetric solution of Einstein's equations sourced by a cloud of strings (CoS) and a dark matter (DM) halo modeled by a…

General Relativity and Quantum Cosmology · Physics 2025-09-16 Faizuddin Ahmed , Abdelmalek Bouzenada , Edilberto O. Silva

We explicitly describe the last stages of black hole evaporation in the context of string theory : the combined study of Quantum Field Theory (QFT) and String Theory (ST) in curved backgrounds allows us to go further in the understanding of…

High Energy Physics - Theory · Physics 2007-05-23 Marina Ramon Medrano , Norma G. Sanchez

In this paper, we present an exact spherically symmetric and Yang-Mills charged AdS black hole solution in the context of $4D$ Einstein-Gauss-Bonnet (EGB) gravity in the presence of a cloud of strings. The regularity of the solution is…

High Energy Physics - Theory · Physics 2026-05-26 Faramarz Rahmani , Mehdi Sadeghi

A family of exact conformal field theories is constructed which describe charged black strings in three dimensions. Unlike previous charged black hole or extended black hole solutions in string theory, the low energy spacetime metric has a…

High Energy Physics - Theory · Physics 2009-10-22 James H. Horne , Gary T. Horowitz

In the context of $f(R)$ gravity theories, the issue of finding static and spherically symmetric black hole solutions is addressed. Two approaches to study the existence of such solutions are considered: first, constant curvature solutions,…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Alvaro de la Cruz-Dombriz , Antonio Dobado , Antonio L. Maroto

We solve the dilaton field equation in the background of a spherically symmetric black hole in type II superstring theory with $\alpha'^3$ corrections in arbitrary $d$ spacetime dimensions. We then apply this result to obtain a spherically…

High Energy Physics - Theory · Physics 2019-04-17 Filipe Moura

The amount of the Hawking radiation in Hartle-Hawking vacuum around the Schwarzschild black hole is calculated in the presence of the cloud of virtual-cosmic-string loops near the black hole. Recently, Coleman, Preskill and Wilczek have…

High Energy Physics - Theory · Physics 2012-09-21 Kiyoshi Shiraishi

We recall the existing string theory understanding of black hole entropy and argue it is incomplete but we put forward a modified version, based on the author's 'matter-gravity entanglement hypothesis', which, we claim, gives a more…

General Relativity and Quantum Cosmology · Physics 2012-09-25 Bernard S. Kay

Recently, a coherent picture of the quantum mechanics of an evaporating black hole has been presented which reconciles unitarity with the predictions of the equivalence principle. The thermal nature of a black hole as viewed in a distant…

High Energy Physics - Theory · Physics 2020-04-01 Yasunori Nomura

The Dymnikova black hole represents a regular spacetime solution interpolating between a de Sitter core and an asymptotically Schwarzschild geometry. In this work, we investigate a generalized Dymnikova black hole surrounded by perfect…

General Relativity and Quantum Cosmology · Physics 2026-02-27 Faizuddin Ahmed , Sardor Murodov , Bekzod Rahmatov , Abdelmalek Bouzenada

This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Jean-Pierre De Villiers , Valeri Frolov

We consider the first laws of thermodynamics for a pair of systems made up of the two horizons of a Kerr-Newman black hole. These two systems are constructed in such a way that we only demand their ``horizon areas'' to be the sum and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 S. Q. Wu

Two strands of observational gravitation, one the search for astrophysical evidence of primordial black holes and the other the search for gravitational waves, may combine to provide strong evidence in favour of cosmological models based on…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Edmund J. Copeland , Andrew R. Liddle , James E. Lidsey , David Wands

In a recent essay, we discussed the possibility of using polymer sizing to model the collapse of a single, long excited string to a black hole. In this letter, we apply this idea to bring further support to string/black hole correspondence.…

High Energy Physics - Theory · Physics 2009-10-31 Ramzi R. Khuri

It is expected that when the string coupling is taken to be sufficiently small, a black hole turns into a bound state of self-gravitating fundamental strings. This state would be described by winding strings wrapping around the Euclidean…

High Energy Physics - Theory · Physics 2025-06-23 Akihiro Ishibashi , Yoshinori Matsuo , Akane Tanaka

We generalize the results of a previous paper by one of the authors to show a relationship among a class of string solutions through $O(\tilde d, \tilde d)$ transformations. The results are applied to a rotating black hole solution of three…

High Energy Physics - Theory · Physics 2010-11-01 Abbas Ali , Alok Kumar

The modes of vibration of hanging and partially supported strings provide useful analogies to scalar fields travelling through spacetimes that admit conformally flat spatial sections. This wide class of spacetimes includes static,…

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

String theory on 2-d charged black holes corresponding to (SL(2)xU(1)_L)/U(1) exact asymmetric quotient CFTs are investigated. These backgrounds can be embedded, in particular, in a two dimensional heterotic string. In the extremal case,…

High Energy Physics - Theory · Physics 2008-11-26 Amit Giveon , Amit Sever

The existence and stability under linear perturbation of closed timelike curves in the spacetime associated to Schwarzschild black hole pierced by a spinning string are studied. Due to the superposition of the black hole, we find that the…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Valeria M. Rosa , Patricio S. letelier

A spherically symmetric black hole solution defined by the gravitational mass is explored in higher-order curvature gravity associated with a scalar field. It is demonstrated that the singularities of the curvature invariants will be far…

General Relativity and Quantum Cosmology · Physics 2025-09-04 G. G. L. Nashed , Usman Zafar , Kazuharu Bamba