English
Related papers

Related papers: Static Spherically Symmetric Solutions in F(R) Gra…

200 papers

A new solution with constant torsion is derived using the field equations of f(T). Asymptotic forms of energy density, radial and transversal pressures are shown to meet the standard energy conditions, i.e., weak and null energy conditions…

General Physics · Physics 2016-10-24 Gamal G. L. Nashed

We study properties of static spherically symmetric solutions in $f(\mathbb T)$ gravity. Based on our previous work on generalising Bianchi identities for this kind of theories, we show how this search of solutions can be reduced to the…

General Relativity and Quantum Cosmology · Physics 2021-05-03 Alexey Golovnev , Maria-Jose Guzman

We consider static, spherically symmetric vacuum solutions to the equations of a theory of gravity with the Lagrangian f(R) where R is the scalar curvature and f is an arbitrary function. Using a well-known conformal transformation, the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. A. Bronnikov , M. S. Chernakova

A general approach to find out exact cosmological solutions in f(R)-gravity is discussed. Instead of taking into account phenomenological models, we assume, as a physical criterium, the existence of Noether symmetries in the cosmological…

General Relativity and Quantum Cosmology · Physics 2010-02-10 Salvatore Capozziello , Antonio De Felice

A Lagrangian formalism is used to study the motion of a spinning massive particle in Friedmann--Robertson--Walker and G\"odel spacetimes, as well as in a general Schwarzschild-like spacetime and in static spherically symmetric conformally…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Nicolas Zalaquett , Sergio A. Hojman , Felipe A. Asenjo

Axially symmetric solutions for f (R)-gravity can be derived starting from exact spherically sym- metric solutions achieved by Noether symmetries. The method takes advantage of a complex coordi- nate transformation previously developed by…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Salvatore Capozziello , Mariafelicia De Laurentis , Arturo Stabile

We consider modified $f(R)$ gravity with a kinetic curvature scalar as a chiral self-gravitating model in a spherically symmetric spacetime. Most attention devoted to finding solutions for special case of scaling transformation when…

General Relativity and Quantum Cosmology · Physics 2020-08-11 Sergey Chervon , Julio Fabris , Igor Fomin

Various formulations of smooth-particle hydrodynamics (SPH) have been proposed, intended to resolve certain difficulties in the treatment of fluid mixing instabilities. Most have involved changes to the algorithm which either introduce…

Instrumentation and Methods for Astrophysics · Physics 2018-06-19 Philip F. Hopkins

We discuss vacuum static, spherically symmetric asymptotically flat solutions of the generalized hybrid metric-Palatini theory of gravity (generalized HMPG) suggested by B\"ohmer and Tamanini, involving both a metric $g_{\mu\nu}$ and an…

General Relativity and Quantum Cosmology · Physics 2023-11-14 K. A. Bronnikov , S. V. Bolokhov , M. V. Skvortsova

We consider cosmological properties of modified gravity with nonlocal term $ R^p\mathcal{F}(\Box)R^q$ in its Lagrangian. Equations of motion are presented. For the flat FLRW metric, and some particular values of natural numbers $p$ and $q$…

General Relativity and Quantum Cosmology · Physics 2016-04-26 Ivan Dimitrijevic

Equations of motion of low-energy effective theories of quantum electrodynamics include infinitely many interaction terms, which make them difficult to solve. The self-duality property has facilitated research on the solutions to these…

High Energy Physics - Theory · Physics 2015-06-04 Hironobu Kihara

We investigate static cylindrically symmetric vacuum solutions in Weyl coordinates in the framework of f(T) theories of gravity, where T is the torsion scalar. The set of modified Einstein equations is presented and the fourth coming…

General Physics · Physics 2013-01-15 M. J. S. Houndjo , D. Momeni , R. Myrzakulov

We present an exact stationary {\it axially symmetric} vacuum solution of metric-affine gravity (MAG) which generalises the recently reported spherically symmetric solution. Besides the metric, it carries nonmetricity and torsion as…

General Relativity and Quantum Cosmology · Physics 2009-10-28 E. J. Vlachynsky , R. Tresguerres , Yu. N. Obukhov , F. W. Hehl

It is shown that an arbitrary static, spherically symmetric metric can be presented as an exact solution of a scalar-tensor theory (STT) of gravity with certain nonminimal coupling function $f(\phi)$ and potential $U(\phi)$. The scalar…

General Relativity and Quantum Cosmology · Physics 2023-11-14 Kirill A. Bronnikov , Kodir Badalov , Rustam Ibadov

In this article we obtain wormhole solutions in the recently proposed extension of symmetric teleparallel gravity called $f(Q,T)$ gravity. Here, the gravitational Lagrangian $L$ is defined by an arbitrary function $f$ of $Q$ and $T$ (where…

General Relativity and Quantum Cosmology · Physics 2022-08-23 Moreshwar Tayde , Zinnat Hassan , P. K. Sahoo , Sashideep Gutti

Nonlocal terms in the Einstein Hilbert(EH) action appears as IR corrections in effective theory of quantum gravity. Here we have considered such an action keeping the terms which are quadratic in Ricci Scalar. We obtain the solution for a…

General Relativity and Quantum Cosmology · Physics 2018-10-10 Utkarsh Kumar , Sukanta Panda

First we review some of the attempts made to find exact spherically symmetric solutions of Einstein field equations in the presence of scalar fields .Wyman solution in both static and non static scalar field is discussed briefly and it is…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Mohammad Mehrpooya , D. Momeni

We study static cylindrically symmetric vacuum solutions in Weyl coordinates in the context of the metric f(R) theories of gravity. The set of the modified Einstein equations is reduced to a single equation and it is shown how one can…

General Relativity and Quantum Cosmology · Physics 2008-12-18 A. Azadi , D. Momeni , M. Nouri-Zonoz

A static, asymptotically flat, spherically symmetric solutions is investigated in f(R) theories of gravity for a charged black hole. We have studied the weak field limit of f(R) gravity for the some f(R) model such as f(R) = R + epsilon…

General Relativity and Quantum Cosmology · Physics 2011-09-13 A. Aghamohammadi , Kh. Saaidi , M. R. Abolhasani , A. Vajdi

We discuss static spherically symmetric solutions in a recently proposed non-local infrared modification of Einstein equations induced by a term $m^2g_{\mu\nu}\Box^{-1} R$, where $m$ is a mass scale. We find that, contrary to what happens…

High Energy Physics - Theory · Physics 2015-06-18 Alex Kehagias , Michele Maggiore