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相关论文: Some Cosmological Solutions of a Nonlocal Modified…

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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…

广义相对论与量子宇宙学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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,…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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.…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

高能物理 - 理论 · 物理学 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…

数学物理 · 物理学 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…

高能物理 - 理论 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 2019-07-17 Igor V. Fomin , Sergey V. Chervon