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Related papers: Cosmological Solutions in Nonlocal Models

200 papers

We consider non-local modifications of General Relativity given by a distortion function in terms of the inverse of the d'Alembert operator. The inclusion of these terms is motivated by the possibility of reproducing the current accelerated…

General Relativity and Quantum Cosmology · Physics 2023-10-06 Salvatore Capozziello , Rocco D'Agostino

We investigate f(R)-gravity models performing the ADM-slicing of standard General Relativity. We extract the static, spherically-symmetric vacuum solutions in the general case, which correspond to either Schwarzschild de-Sitter or…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-07 Sayan K. Chakrabarti , Emmanuel N. Saridakis , Anjan A. Sen

Anisotropic cosmological models are investigated in the frame work of $f(R)$ gravity in the metric formalism. Plane symmetric models are considered to incorporate anisotropy in the expansion rates along different spatial directions. The…

General Relativity and Quantum Cosmology · Physics 2017-04-26 S K Tripathy , B Mishra

In this paper we present a number of examples of exact solutions for the Friedmann cosmological equation for metric $ F(R) $ gravity model. Emphasis was placed on the possibility of obtaining exact time dependences of the main cosmological…

General Relativity and Quantum Cosmology · Physics 2024-01-31 Maria Shubina

In this paper, we briefly review highlights of nonlocal de Sitter gravity based on the nonlocal term $ \sqrt{R - 2\Lambda}\ \mathcal{F}(\Box)\ \sqrt{R - 2\Lambda }$ in the Einstein-Hilbert action without matter sector. This nonlocal de…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Ivan Dimitrijevic , Branko Dragovich , Zoran Rakic , Jelena Stankovic

The resolution of the problem of cosmological singularity in the framework of gauge theories of gravitation is discussed. Generalized cosmological Friedmann equations for homogeneous isotropic models filled by interacting scalar fields and…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Albert V. Minkevich

We consider Noether symmetry approach to find out exact cosmological solutions in $f(T)$-gravity. Instead of taking into account phenomenological models, we apply the Noether symmetry to the $f(T)$ gravity. As a result, the presence of such…

General Physics · Physics 2012-05-29 K. Atazadeh , F. Darabi

In this paper we consider the two-dimensional metric $f(R)$-gravity model for the metric tensor depending on two variable: time and one spacelike coordinate. We obtain exact analytical vacuum solutions for different forms of function $ f(R)…

General Relativity and Quantum Cosmology · Physics 2021-05-18 Maria Shubina

This paper is devoted to investigate the recently proposed modified Gauss-Bonnet $f(\mathcal{G},T)$ gravity, with $\mathcal{G}$, the Gauss-Bonnet term, coupled with ${T}$, the trace of energy-momentum tensor. We have used the Noether…

General Relativity and Quantum Cosmology · Physics 2017-07-12 M. Farasat Shamir , Mushtaq Ahmad

We explore some of the cosmological implications of the recent classical nonlocal generalization of Einstein's theory of gravitation in which nonlocality is due to the gravitational memory of past events. In the Newtonian regime of this…

General Relativity and Quantum Cosmology · Physics 2016-08-24 C. Chicone , B. Mashhoon

We investigate the main features of the flat Friedmann-Lema{\i}tre-Robertson-Walker cosmological models in the f(T) teleparallel gravity. In particular, a general approach to find out exact cosmological solutions in f (T) gravity is…

General Relativity and Quantum Cosmology · Physics 2015-06-17 S. Basilakos , S. Capozziello , M. De Laurentis , A. Paliathanasis , M. Tsamparlis

We present a new bouncing cosmological solution of the non-local theory known as infinite derivative gravity, which goes beyond the recursive ansatz, ${\Box R = r_1 R +r_2}$. The non-local field equations are evaluated using the spectral…

General Relativity and Quantum Cosmology · Physics 2022-02-24 Ivan Kolář , Francisco José Maldonado Torralba , Anupam Mazumdar

Dark energy cosmology is considered in a modified Gauss-Bonnet (GB) model of gravity where an arbitrary function of the GB invariant, $f(G)$, is added to the General Relativity action. We show that such theory is endowed with a quite rich…

High Energy Physics - Theory · Physics 2008-11-26 Guido Cognola , Emilio Elizalde , Shin'ichi Nojiri , Sergei D. Odintsov , Sergio Zerbini

Within the framework of the local limit of nonlocal gravity (NLG), we investigate a class of Bianchi type I spatially homogeneous but anisotropic cosmological models. The modified field equations are presented in this case and some special…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Javad Tabatabaei , Abdolali Banihashemi , Shant Baghram , Bahram Mashhoon

In a homogenous and isotropic cosmology, we introduce general exact solutions for some modified gravity models. In particular, we introduce exact solutions for power-law $f(R)$ gravity and Brans-Dicke theory in Einstein and Jordan conformal…

High Energy Physics - Theory · Physics 2018-06-08 Yousef Bisabr

$f(R)$ modifications of Einstein's gravity is an interesting possibility to explain the late time acceleration of the Universe. In this work we explore the cosmological viability of one such $f(R)$ modification proposed in (Kruglov:2013).…

General Relativity and Quantum Cosmology · Physics 2016-07-13 Koushik Dutta , Sukanta Panda , Avani Patel

This work investigates alternative theories of gravity, the solutions to their field equations and the constraints that can be imposed upon them from observation and experiment. Specifically, we consider the cosmologies and spherically…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Clifton

A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions…

General Relativity and Quantum Cosmology · Physics 2016-03-16 A. A. Kobtsev , V. D. Ivashchuk , K. K. Ernazarov

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

We reconcile seemingly conflicting statements in the literature about the behavior of cosmological solutions in modified theories of gravity where the Einstein-Hilbert Lagrangian for gravity is modified by the addition of a function of the…

Astrophysics · Physics 2008-11-26 Ignacy Sawicki , Wayne Hu