2024 Exact solutions in f r theory of gravity

Exact solutions in f r theory of gravity

Author: xagk

August undefined, 2024

WebOct 15, 2008 · arXiv: General Relativity and Quantum Cosmology We review the state of the art of f (R) theories of gravity (in their various formulations), which have been proposed as an explanation of the cosmic acceleration alternative to dark energy. WebWe find a new method for looking for the static and spherically symmetric solutions in F( R) theory of gravity. With this method, a number of new solutions in terms of the analytic …

f(R) gravity - Wikipedia

WebApr 13, 2024 · The purpose of this paper is to study the Kaluza-Klein universe in the context of the f (R, T) gravity theory using magnetized strange quark matter (MSQM). To obtain exact solutions of field equations, we assume two types of volumetric expansion: power law and exponential law volumetric expansions. The violation of energy conditions has … WebJul 4, 2012 · Among the various modifications, f ( R) theory of gravity is treated most suitable due to cosmologically important f ( R) models. It has been suggested that cosmic acceleration can be achieved by replacing the Einstein-Hilbert action of general relativity with a general function Ricci scalar, f ( R ). the brewshall torrance c.a

Galaxies Free Full-Text Bianchi Type I Cosmological Models in ...

WebDec 5, 2014 · The main purpose of this paper is to investigate the exact solutions of cylindrically symmetric spacetime in the context of f(R,T) gravity (Harko et al. in Phys. Rev. D 84:024020, 2011), where f(R,T) is an arbitrary function of Ricci scalar R and trace of the energy momentum tensor T. We explore the exact solutions for two different classes of … Webcoupling constant, this method is applicable to f(R) gravity in the Einstein frame. Also in the recent years some exact solutions for static spherically symmetric perfect ﬂuid in f(R) theory of gravity are presented [9, 10, 11]. Since the ﬁeld equations of f(R) theory are diﬀerential equations of fourth order, more integration 1 WebDec 9, 2008 · In this work, exact solutions of static and spherically symmetric space-times are analyzed in f (R) modified theories of gravity coupled to nonlinear electrodynamics. … the brewseum honolulu

Phys. Rev. D 78, 124007 (2008) - Exact solutions of $f(R)

Exact solutions of (deformed) Jackiw–Teitelboim gravity

WebAug 24, 2014 · Exact solutions of three dimensional black holes: Einstein gravity vs F (R) gravity S. H. Hendi, B. Eslam Panah, R. Saffari In this paper, we consider Einstein gravity in the presence of a class of nonlinear electrodynamics, called … Webtrace of energy–momentum tensor T in f(R,T)theory of gravity. We assume that f(R,T) = f(R)+2 f(T)with f(R) = R and f(T) = λT where λ is a constant, R and T are the Ricci scalar and trace of energy–momentum tensor. First, we obtain an exact solution of the bulk viscous Universe in f(R,T)gravity, then we use observational the brewskiWebApr 10, 2024 · Anisotropic Solutions in Symmetric Teleparallel $f\left( Q\right)$-theory: Kantowski-Sachs and Bianchi III LRS Cosmologies the brewsline

"Webparameters to develop a minimal background about f(G,T) theory of gravity. The exact bouncing solutions with physical analysis are provided with the choice of two equation of state parameters. ... literature to obtain some interesting results while studying f(R,T) theory of gravity [41]. The evolution of Hubble parameter is shown in Fig. 1 for ... " - Exact solutions in f r theory of gravity

Exact solutions in f r theory of gravity

WebJul 8, 2024 · Exact solutions of an -theory (of gravity) in a static central (gravitational) field have been studied in the literature quite well, but, to find and study exact solutions in the case of a non-static central field are not easy at all. WebBy imposing a maximal pressure condition, an exact solution for each scalar field potential, describing the initial state of the universe, was found. ... Nojiri, S.; Odintsov, S.D. Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models. Phys. Rep. 2011, 505, 59–114. [Google Scholar]

Did you know?

Webf ( R) gravity as presented in the previous sections is a scalar modification of general relativity. More generally, we can have a coupling involving invariants of the Ricci tensor and the Weyl tensor. Special cases are f ( R) gravity, conformal gravity, Gauss–Bonnet gravity and Lovelock gravity. WebWe find a new method for looking for the static and spherically symmetric solutions in F(R) theory of gravity. With this method, a number of new solutions in terms of the analytic functions are obtained. ... {Exact solutions in F(R) theory of gravity}, author={Changjun Gao and You-gen Shen}, journal={General Relativity and Gravitation}, year ...

WebOct 1, 2024 · The aim of this manuscript is to discuss the wormhole geometry in f (R) theory of gravity, where R represents the Ricci scalar. For our current work, we consider the spherically symmetric static spacetime with an anisotropic fluid source to discuss the wormhole solutions. We further discuss the existence of wormholes by using two well … WebFeb 22, 2024 · Momeni [ 33] obtained a two-parameter family of exact solutions which contains a cosmological constant and proved that in f ( R) gravity the constant curvature solution in cylindrically symmetric cases is only one member of the most generalized Tian family in General relativity.

WebOct 1, 2024 · We have shown that the effect of f (R)-gravity on the temperature adds a coefficient of 1/2 to the cosmological constant. 1 We study the quasinormal modes … WebApr 12, 2024 · The dRGT massive gravity represents a comprehensive theory which properly describes massive graviton field. Latterly, the exact spherical solutions are identified for the black hole in the dRGT massive gravity theory. In this paper, we derive Bousso’s D-bound entropy for the black hole solutions of dRGT massive gravity. By an …

WebOct 1, 2024 · In this section, we will discuss the solutions of non-commutative wormhole geometry by using Lorentzian distribution. For this purpose, we consider the energy density (ED) of SSS and PGS as [64] (17) ρ = θ M π 2 θ + r 2 2. The Lorentzian distribution of PGS (17) is positive due to the non-commutative parameter θ > 0.

Webwhere the prime denotes the derivative with respect to r. 2.2 Exact solutions The Lagrangian density of F(R) theory of gravity takes the form L = F(R). (7) Compared to … the brewster book manuscriptWebJun 1, 2024 · space-times in f (R) theory of gravity and obtained two exact solutions corresponding to two cases as (namely n = 0 and n 6 = 0 ). Also, we assume the power … the brewster angle for the glass airWebJun 22, 2024 · of f(R) theory of gravity. The EFEs in a homogeneous and isotropic space-time give rise to the Friedmann equations that describe the evolution of the universe. In … the brewster angleWebFeb 26, 2016 · We find a new method for looking for the static and spherically symmetric solutions in $F(R)$ theory of gravity. With this method, a number of new solutions in … the brewster angle is expressed asThe Lagrangian density of F(R) theory of gravity takes the form Compared to struggling with the Einstein equations, it is much more convenient to directly vary the action with respect to U and f, respectively. By so doing, we find the equations of motion are Here F_{,R}\equiv \frac{dF}{dR}. We have only two … See more In general, the metric of a four dimensional, static and spherically symmetric spacetime takes the form of where x plays the role of radial variable and d\Omega ^2 is … See more In this section, let us study the structure of spacetime generally from Eq. (15). We find in general, there are two event horizons and one curvature singularity in the spacetimes. Furthermore, a deficit angle always exists in the … See more the brewmaster\u0027s taproom rentonWebThis modiﬁed gravitational theory belongs to a more general family known as f (R)-theory of gravity [8–10]. The new degrees of freedom, which follow from the modiﬁcation of the ... we are interested in the investigation of self-similar exact solutions in f (Q)-theory for anisotropic cosmological models. Speciﬁcally, for the Kantowski ... the brewseum the brewster brothers