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Deformed Reissner-Nordstr\"om, as well as Reissner-Nordstr\"om de Sitter, solutions are obtained in a noncommutative gauge theory of gravitation. The gauge potentials (tetrad fields) and the components of deformed metric are calculated to…

High Energy Physics - Theory · Physics 2008-11-26 M. Chaichian , M. R. Setare , A. Tureanu , G. Zet

We discuss static spherically symmetric solutions in a recently proposed non-local infrared modification of Einstein equations induced by a term $m^2g_{\mu\nu}\Box^{-1} R$, where $m$ is a mass scale. We find that, contrary to what happens…

High Energy Physics - Theory · Physics 2015-06-18 Alex Kehagias , Michele Maggiore

We consider non-local Integral Kernel Theories of Gravity in a homogeneous and isotropic universe background as a possible scenario to drive the cosmic history. In particular, we investigate the cosmological properties of a gravitational…

General Relativity and Quantum Cosmology · Physics 2024-09-02 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

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

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

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 show that modifications of Einstein gravity during inflation could leave potentially measurable imprints on cosmological observables in the form of non-Gaussian perturbations. This is due to the fact that these modifications appear in…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 Nicola Bartolo , Dario Cannone , Raul Jimenez , Sabino Matarrese , Licia Verde

A classical nonlocal generalization of Einstein's theory of gravitation has recently been developed via the introduction of a scalar causal "constitutive" kernel that must ultimately be determined from observational data. It turns out that…

Astrophysics of Galaxies · Physics 2014-05-14 S. Rahvar , B. Mashhoon

Versions of parameterized pseudo-Newtonian gravity theories specially designed for cosmology have been introduced in recent cosmology literature. The modifications demand a zero-pressure fluid in the context of versions of modified…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Jai-chan Hwang , Hyerim Noh , Chan-Gyung Park

Noncommutative geometry, as conceptualized by Nicolini, Smailagic, and Spallucci, may be viewed as a slight modification of Einstein's theory. The same can be said for $f(R)$ modified gravity for an appropriate choice of the function…

General Relativity and Quantum Cosmology · Physics 2021-01-05 Peter K. F. Kuhfittig

This is a first study of the cosmology of classical fractional gravity, a nonlocal proposal endowed with self-adjoint fractional d'Alembertian operators which serves as the basis for an ultraviolet-complete theory of quantum gravity. We…

General Relativity and Quantum Cosmology · Physics 2026-05-01 Iván Salvador-García , Gianluca Calcagni

We construct a model in which the cosmological constant is canceled from the gravitational equations of motion. Our model relies on two key ingredients: a nonlocal constraint on the action, which forces the spacetime average of the…

High Energy Physics - Theory · Physics 2017-07-04 Sean M. Carroll , Grant N. Remmen

It is well known that the Einstein-Hilbert action in two dimensions is topological and yields an identically vanishing Einstein tensor. Consequently one is faced with difficulties when formulating a non-trivial gravity model. We present a…

General Relativity and Quantum Cosmology · Physics 2024-06-10 Christian G. Boehmer , Erik Jensko

Here, we derive the metric for the spacetime around rotating object for the gravity action having nonlocal correction of $R\Box^{-2} R $ to the Einstein-Hilbert action. Starting with the generic stationary, axisymmetric metric, we solve the…

General Relativity and Quantum Cosmology · Physics 2019-01-02 Utkarsh Kumar , Sukanta Panda , Avani Patel

The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein's general relativity could alleviate the different problems associated with it that result…

General Relativity and Quantum Cosmology · Physics 2022-10-14 The FADE Collaboration , Heliudson Bernardo , Benjamin Bose , Guilherme Franzmann , Steffen Hagstotz , Yutong He , Aliki Litsa , Florian Niedermann

Nonlocal gravity models are constructed to explain the current acceleration of the universe. These models are inspired by the infrared correction appearing in Einstein Hilbert action. Here we develop the Hamiltonian formalism of a nonlocal…

General Relativity and Quantum Cosmology · Physics 2021-12-28 Pawan Joshi , Utkarsh Kumar , Sukanta Panda

A new approach for embedding the renormalization group running of Newton's constant and cosmological constant in gravity is proposed. This approach is based on a gravitational Lagrangian that gives rise to a new class of modified gravity…

General Relativity and Quantum Cosmology · Physics 2025-10-28 Alfio Bonanno , Konstantinos F. Dialektopoulos , Vasilios Zarikas

The field equations of the recent nonlocal generalization of Einstein's theory of gravitation are presented in a form that is reminiscent of general relativity. The implications of the nonlocal field equations are studied in the case of…

General Relativity and Quantum Cosmology · Physics 2016-05-24 Donato Bini , Bahram Mashhoon

For a class of viable cosmological models in $f(R)$ gravity which deviation from the Einstein gravity decreases as a inverse power law of the Ricci scalar $R$ for large $R$, an analytic solution for density perturbations in the matter…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-23 Hayato Motohashi , Alexei A. Starobinsky , Jun'ichi Yokoyama

We investigate the cosmological dynamics of nonlocally corrected gravity involving a function of the inverse d'Alembertian acting on the Gauss-Bonnet term. Casting the dynamical equations in local form, we derive the reconstruction…

General Relativity and Quantum Cosmology · Physics 2020-03-12 Emilio Elizalde , Ekaterina O. Pozdeeva , Sergey Yu. Vernov
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