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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

During hundred years of General Relativity (GR), many significant gravitational phenomena have been predicted and discovered. General Relativity is still the best theory of gravity. Nevertheless, some (quantum) theoretical and…

High Energy Physics - Theory · Physics 2017-01-10 Ivan Dimitrijevic , Branko Dragovich , Jelena Stankovic , Alexey S. Koshelev , Zoran Rakic

We consider nonlocal modification of the Einstein theory of gravity in framework of the pseudo-Riemannian geometry. The nonlocal term has the form $\mathcal{H}(R) \mathcal{F}(\Box)\mathcal {G}(R)$, where $\mathcal{H}$ and $\mathcal{G}$ are…

High Energy Physics - Theory · Physics 2015-08-25 Ivan Dimitrijevic , Branko Dragovich , Jelena Grujic , Zoran Rakic

In this work, we scrutinize the consistency of spacetime homogeneous G\"{o}del-type metrics within $f(R,Q,P)$ theories of gravity for well-motivated matter sources. As it is well known, such geometries allow for causality violation. We…

General Relativity and Quantum Cosmology · Physics 2023-04-28 J. R. Nascimento , A. Yu. Petrov , P. J. Porfirio , Ramires N. da Silva

We discuss some main aspects of theories of gravity containing non-local terms in view of cosmological applications. In particular, we consider various extensions of General Relativity based on geometrical invariants as $f(R, \Box^{-1} R)$,…

General Relativity and Quantum Cosmology · Physics 2022-01-13 Salvatore Capozziello , Francesco Bajardi

In this paper, we investigate a nonlocal modification of general relativity (GR) with action $S = \frac{1}{16\pi G} \int [ R- 2\Lambda + (R-4\Lambda) \, \mathcal{F}(\Box) \, (R-4\Lambda) ] \, \sqrt{-g}\; d^4x ,$ where $\mathcal{F} (\Box) =…

General Relativity and Quantum Cosmology · Physics 2020-06-30 I. Dimitrijevic , B. Dragovich , A. S. Koshelev , Z. Rakic , J. Stankovic

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 considered. The model is proven to have de…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-08 E. Elizalde , E. O. Pozdeeva , S. Yu. Vernov

Non-local theories of gravity have recently gained a lot of interest because they can suitably represent the behavior of gravitational interaction in the ultraviolet regime. Furthermore, at infrared scales, they give rise to notable…

Astrophysics of Galaxies · Physics 2019-03-06 K. F. Dialektopoulos , D. Borka , S. Capozziello , V. Borka Jovanović , P. Jovanović

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

Nonlocal gravity is a promising super-renormalizable or finite quantum gravity theory consistent with unitarity. In this paper, we focus on the classical equations of motion and explicitly show that a particular subclass of G\"{o}del-type…

General Relativity and Quantum Cosmology · Physics 2026-05-05 Zhe Zhao , Leonardo Modesto , Cosimo Bambi

We address the homogeneous in space and time (ST-homogeneous) G\"{o}del-type metrics within the cubic galileon theory, a particular class of generalized galileon theories. We check the consistency of such spacetimes for a physically…

General Relativity and Quantum Cosmology · Physics 2020-11-26 J. R. Nascimento , A. Yu. Petrov , P. Porfírio , A. F. Santos

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

A general class of f(R) gravity models with minimally coupling a nonlocal scalar field is considered. The Ostrogradski representation for nonlocal gravitational models with a quadratic potential and the way of its localization are proposed.…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-26 Sergey Yu. Vernov

The properties of static, spherically symmetric configurations are considered in the framework of two models of nonlocally corrected gravity, suggested in S. Deser and R. Woodard., Phys. Rev. Lett. 663, 111301 (2007), and S. Capozziello et…

High Energy Physics - Theory · Physics 2010-04-06 K. A. Bronnikov , E. Elizalde

This chapter of the Handbook of Quantum Gravity aims to illustrate how nonlocality can be implemented in field theories, as well as the manner it solves fundamental difficulties of gravitational theories. We review Stelle's quadratic…

High Energy Physics - Theory · Physics 2022-11-11 Arnau Bas i Beneito , Gianluca Calcagni , Lesław Rachwał

A non-local modified gravity model with an analytic function of the d'Alembert operator is considered. This model has been recently proposed as a possible way of resolving the singularities problem in cosmology. We present an exact bouncing…

High Energy Physics - Theory · Physics 2012-09-18 Alexey S. Koshelev , Sergey Yu. Vernov

[Abridged] In its standard formulation, the $f(T)$ field equations are not invariant under local Lorentz transformations, and thus the theory does not inherit the causal structure of special relativity. A locally Lorentz covariant $f(T)$…

General Relativity and Quantum Cosmology · Physics 2017-11-28 G. Otalora , M. J. Reboucas

A non-local gravity model, which includes a function $f(\Box^{-1} R)$, where $\Box$ is the d'Alembert operator, is considered. For the model with an exponential $f(\Box^{-1} R)$ de Sitter solutions are explored, without any restrictions on…

General Relativity and Quantum Cosmology · Physics 2019-10-30 E. Elizalde , E. O. Pozdeeva , S. Yu. Vernov

We propose a nonlocal field theory for gravity in presence of matter consistent with perturbative unitarity, quantum finiteness, and other essential classical properties that we are going to list below. First, the theory exactly reproduces…

General Relativity and Quantum Cosmology · Physics 2021-03-09 Leonardo Modesto

A new representation is found for the action of the recently suggested ghost-free nonlocal gravity models generating de Sitter or Anti-de Sitter background with an arbitrary value of the effective cosmological constant. This representation…

High Energy Physics - Theory · Physics 2015-06-11 A. O. Barvinsky , Yu. V. Gusev
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