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The Newtonian approximation with a nonvanishing nonlocal background field is analyzed for the scalar-tensor nonlocal gravity and nonlocal Gauss-Bonnet gravity. For these two theories, our calculations show that the Newtonian gravitational…

General Relativity and Quantum Cosmology · Physics 2019-03-28 S. X. Tian , Zong-Hong Zhu

A nonlocal gravity model with a function $f(\Box^{-1} R)$, where $\Box$ is the d'Alembert operator, is considered. The algorithm, allowing to reconstruct $f(\Box^{-1} R)$, corresponding to the given Hubble parameter and the state parameter…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-18 Sergey Yu. Vernov

Motivated by conventional gauge theories, we consider a theory of gravity in which the Einstein-Hilbert action is replaced by a term that is quadratic in the Riemann tensor. We focus on cosmological solutions to the field equations in flat,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. Lasenby , C. J. L. Doran , R. Heineke

We consider extensions of General Relativity based on the non-local function $f(R, \Box^{-1} R)$, where $R$ is the Ricci curvature scalar and the non-locality is due to the term $\Box^{-1} R$. We focus on cosmological minisuperspaces and…

General Relativity and Quantum Cosmology · Physics 2022-01-19 Adriano Acunzo , Francesco Bajardi , Salvatore Capozziello

A nonlocal generalization of Einstein's theory of gravitation is constructed within the framework of the translational gauge theory of gravity. In the linear approximation, the nonlocal theory can be interpreted as linearized general…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Friedrich W. Hehl , Bahram Mashhoon

We consider the G\"odel universe within the context of the local limit of nonlocal gravity. This theory differs from Einstein's general relativity (GR) through the existence of a scalar susceptibility function $S(x)$ that is a…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Z. Mardaninezhad , B. Mashhoon

The analysis of measurements of accelerated observers in Minkowski spacetime has led to the development of nonlocal special relativity theory. Inertia and gravitation are intimately connected in accordance with the principle of equivalence.…

General Relativity and Quantum Cosmology · Physics 2012-10-11 Bahram Mashhoon

A nonlocal gravity model (2.1) was introduced and considered recently [49], and two exact cosmological solutions in flat space were presented. The first solution is related to some radiation effects generated by nonlocal dynamics on dark…

General Relativity and Quantum Cosmology · Physics 2022-01-07 Ivan Dimitrijevic , Branko Dragovich , Zoran Rakic , Jelena Stankovic

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

Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation developed in close analogy with the nonlocal electrodynamics of media. It appears that the nonlocal aspect of the universal gravitational…

General Relativity and Quantum Cosmology · Physics 2022-09-12 Mahmood Roshan , Bahram Mashhoon

A nonlocal gravity model which does not assume the existence of a new dimensional parameter in the action and includes a function $f(\Box^{-1} R)$, with $\Box$ the d'Alembertian operator, is studied. By specifying an exponential form for…

High Energy Physics - Theory · Physics 2013-07-24 Emilio Elizalde , Ekaterina O. Pozdeeva , Sergey Yu. Vernov , Ying-li Zhang

Certain off-diagonal vacuum and nonvacuum configurations in Einstein gravity can mimic physical effects of modified gravitational theories of $ f(R,T,R_{\mu\nu}T^{\mu\nu})$ type. We prove this statement by constructing exact and approximate…

Mathematical Physics · Physics 2015-06-30 Emilio Elizalde , Sergiu I. Vacaru

We present a class of generally covariant nonlocal gravity models which have a flat-space general relativistic (GR) limit and also possess a stable de Sitter (dS) or Anti-de Sitter (AdS) background with an arbitrary value of its…

High Energy Physics - Theory · Physics 2013-05-30 Andrei O. Barvinsky

Off-diagonal vacuum and nonvacuum configurations in Einstein gravity can mimic physical effects of modified gravitational theories of $f(R,T,R_{\mu \nu}T^{\mu \nu})$ type. To prove this statement, exact and approximate solutions are…

General Relativity and Quantum Cosmology · Physics 2015-07-01 Emilio Elizalde , Sergiu I. Vacaru

A nonlocal gravity model is considered which does not assume the existence of a new dimensional parameter in the action and includes a function $f(\Box^{-1} R)$, with $\Box$ the d'Alembertian operator. Using a reconstruction procedure for…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-06 E. Elizalde , E. O. Pozdeeva , S. Yu. Vernov

In this work, we analyzed the improved Deser-Woodard non-local gravity over the background of five different bouncing cosmologies, whose premise is avoid the initial singular state of the universe. We developed the numerical solution for…

General Relativity and Quantum Cosmology · Physics 2022-06-01 D. Jackson , R. Bufalo

The present work deals with scalar field cosmology in the framework of a quantum gravity modified Einstein-Hilbert Lagrangian with variable $G$ and $\Lambda$. Using Renormalization group, variable $G$ behaves as a minimally coupled filed…

General Relativity and Quantum Cosmology · Physics 2019-11-22 Santu Mondal , Sourav Dutta , Subenoy Chakraborty

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

The recent nonlocal generalization of Einstein's theory of gravitation reduces in the Newtonian regime to a nonlocal and nonlinear modification of Poisson's equation of Newtonian gravity. The nonlocally modified Poisson equation implies…

General Relativity and Quantum Cosmology · Physics 2015-06-03 C. Chicone , B. Mashhoon

We study the special class of the exact solutions in cosmological models based on the Generalized Scalar-Tensor Gravity with non-minimal coupling of a scalar field to the Ricci scalar and to the Gauss-Bonnet scalar in 4D Friedmann universe…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Igor V. Fomin , Sergey V. Chervon