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Related papers: On Nonlocal Modified Gravity and Cosmology

200 papers

We propose a nonlocal scalar-tensor model of gravity with pseudodifferential operators inspired by the effective action of p-adic string and string field theory on flat spacetime. An infinite number of derivatives act both on the metric and…

High Energy Physics - Theory · Physics 2010-12-28 Gianluca Calcagni , Giuseppe Nardelli

Cosmology is a field of physics in which the use of General Relativity theory is indispensable. However, a cosmology based on Newtonian gravity theory for gravity is possible in certain circumstances. The applicability of Newtonian theory…

Space Physics · Physics 2013-12-04 J. C. Fabris , Hermano Velten

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

We describe a wide class of inhomogeneous relativistic solutions that are well approximated on cosmological scales by solutions of Newtonian gravity. Error estimates measuring the difference between the Newtonian and relativistic solutions…

General Relativity and Quantum Cosmology · Physics 2014-06-06 Todd A. Oliynyk

Loop Quantum Gravity is a background independent, nonperturbative approach to the quantization of General Relativity. Its application to models of interest in cosmology and astrophysics, known as Loop Quantum Cosmology, has led to new and…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Guillermo A. Mena Marugan

A brief account of the present status of the recent nonlocal generalization of Einstein's theory of gravitation is presented. The main physical assumptions that underlie this theory are described. We clarify the physical meaning and…

General Relativity and Quantum Cosmology · Physics 2015-01-20 B. Mashhoon

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 perform a detailed dynamical analysis of various cosmological scenarios in extended (varying-mass) nonlinear massive gravity. Due to the enhanced freedom in choosing the involved free functions, this cosmological paradigm allows for a…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-05 Genly Leon , Joel Saavedra , Emmanuel N. Saridakis

The experimental results that test Bell's inequality have found strong evidence suggesting that there are nonlocal aspects in nature. Evidently, these nonlocal effects, which concern spacelike separated regions, create an enormous tension…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Yuri Bonder , Johas D. Morales

We construct a class of generalized non-local gravity (GNLG) model which is the modified theory of general relativity (GR) obtained by adding a term $m^{2n-2} R\Box^{-n}R$ to the Einstein-Hilbert action. Concretely, we not only study the…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Xue Zhang , Ya-Bo Wu , Song Li , Yu-Chen Liu , Bo-Hai Chen , Yun-Tian Chai , Shuang Shu

In this paper we make an extensive description of quantum non-locality, one of the most intriguing and fascinating facets of quantum mechanics. After a general presentation of several studies on this subject, we consider if quantum…

Quantum Physics · Physics 2020-07-28 Marco Genovese , Marco Gramegna

We consider the most general quadratic in curvature stringy motivated non-local action for the modified Einstein's gravity. We present exact analytic cosmological solutions including the bouncing ones and develop the relevant techniques for…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-03 Alexey S. Koshelev

We review the exact solutions in modified gravity. It is one of the main problems of mathematical physics for the gravity theory. One can obtain an exact solution if the field equations reduce to a system of ordinary differential equations.…

General Relativity and Quantum Cosmology · Physics 2013-05-27 Andrey N. Makarenko , Valery V. Obukhov

Modifications to gravity can provide attractive alternatives to the dark components of the standard model of cosmology. These modifications to general relativity (GR) must be hidden at small scales where theory is well tested, and so one…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-06 Benjamin Bose

One of the greatest problems of standard cosmology is the Big Bang singularity. Previously it has been shown that non-local ghostfree higher-derivative modifications of Einstein gravity in the ultra-violet regime can admit non-singular…

High Energy Physics - Theory · Physics 2010-12-03 Tirthabir Biswas , Tomi Koivisto , Anupam Mazumdar

We consider a nonlocal gravity model motivated by nonperturbative Quantum Gravity studies. This model, if correct, suggests the existence of strong IR relevant effects which can lead to an interesting late time cosmology. We implement the…

General Relativity and Quantum Cosmology · Physics 2017-11-10 Luca Amendola , Nicolo Burzilla , Henrik Nersisyan

We investigate a particular type of classical nonsingular bouncing cosmology, which results from general relativity if we allow for degenerate metrics. The simplest model has a matter content with a constant equation-of-state parameter and…

General Relativity and Quantum Cosmology · Physics 2019-10-23 F. R. Klinkhamer , Z. L. Wang

We consider certain aspects of cosmological dynamics of a spatially curved Universe in $f(T)$ gravity. Local analysis allows us to find conditions for bounces and for static solutions; these conditions appear to be in general less…

General Relativity and Quantum Cosmology · Physics 2021-06-10 Maria A. Skugoreva , Alexey V. Toporensky

We argue that quantum gravity is nonlocal, first by recalling well-known arguments that support this idea and then by focusing on a point not usually emphasized: that making a conventional effective field theory (EFT) for quantum gravity is…

High Energy Physics - Theory · Physics 2022-01-26 Nicolás Valdés-Meller

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
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