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Related papers: Nonlocal Gravity: Modified Poisson's Equation

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A new computationally efficient method has been introduced to treat self-gravity in mesh based hydrodynamical simulations. It is applied simply by slightly modifying the Poisson equation into an inhomogeneous wave equation. This roughly…

Instrumentation and Methods for Astrophysics · Physics 2016-04-20 Ryosuke Hirai , Hiroki Nagakura , Hirotada Okawa , Kotaro Fujisawa

Gravitational probes should maintain spatial flatness for Einsten-Infeld-Hoffmann dynamics of relativistic matter-energy. The continuous elementary source/particle in Einstein's gravitational theory is the r^{-4} radial energy density…

General Physics · Physics 2008-10-10 I. E. Bulyzhenkov

I propose an alternative $f(R)$ theory of gravity constructed by applying the function $f$ directly to the Ricci tensor instead of the Ricci scalar. The main goal of this study is to derive the resulting modified Einstein equations for the…

General Relativity and Quantum Cosmology · Physics 2017-08-16 Tomasz Stachowiak

A locally Lorentz-covariant theory of gravity that is equivalent to general relativity in weak gravitational field is suggested. The space-time standards in local gravitational field are modified in terms of equivalence principle to keep…

General Relativity and Quantum Cosmology · Physics 2026-02-05 Hai-Long Zhao

A mechanism for emergent gravity on brane solutions in Yang-Mills matrix models is exhibited. Newtonian gravity and a partial relation between the Einstein tensor and the energy-momentum tensor can arise from the basic matrix model action,…

High Energy Physics - Theory · Physics 2014-09-11 Harold Steinacker

Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Salvatore Capozziello , Mariafelicia De Laurentis

This work is focused on searching a geodesic interpretation of the dynamics of a particle under the effects of a Snyder like deformation in the background of the Kepler problem. In order to accomplish that task, a newtonian spacetime is…

General Physics · Physics 2018-05-23 Carlos Leiva

We investigate the cosmological implications of modified gravities induced by the quantum fluctuations of the gravitational metric. If the metric can be decomposed as the sum of the classical and of a fluctuating part, of quantum origin,…

General Relativity and Quantum Cosmology · Physics 2016-08-02 Xing Liu , Tiberiu Harko , Shi-Dong Liang

The observed acceleration of the Universe can be explained by modifying general relativity. One such attempt is the nonlocal model of Deser and Woodard. Here we fix the background cosmology using results from the Planck satellite and…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Scott Dodelson , Sohyun Park

We review some recent developments in the conformal gravity theory that has been advanced as a candidate alternative to standard Einstein gravity. As a quantum theory the conformal theory is both renormalizable and unitary, with unitarity…

High Energy Physics - Theory · Physics 2015-05-27 Philip D. Mannheim

Attempts to merge Einsteinian gravity with Newtonian run into inconsistencies because in Newton's gravity time is absolute and the speed of gravity is infinite. Such an assumption was in a focus of attention of scientists in 19th century…

General Physics · Physics 2015-08-19 Arkady L. Kholodenko

The physical basis of the standard theory of general relativity is examined and a nonlocal theory of accelerated observers is described that involves a natural generalization of the hypothesis of locality. The nonlocal theory is confronted…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bahram Mashhoon

We formulate an approach to the geometry of Riemann-Cartan spaces provided with nonholonomic distributions defined by generic off-diagonal and nonsymmetric metrics inducing effective nonlinear and affine connections. Such geometries can be…

General Relativity and Quantum Cosmology · Physics 2008-12-19 Sergiu I. Vacaru

A generalized geometric method is developed for constructing exact solutions of gravitational field equations in Einstein theory and generalizations. First, we apply the formalism of nonholonomic frame deformations (formally considered for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergiu I. Vacaru

Einstein gravitation theory can be extended by preserving its geometrical nature but changing the relation between curvature and energy-momentum tensors. This change accounts for radiative corrections, replacing the Newton gravitation…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Marc-Thierry Jaekel , Serge Reynaud

A recent theory about the origin of the gravity suggests that the gravity is originally an entropic force. In this work, we discuss the effects of generalized uncertainty principle (GUP) which is proposed by some approaches to quantum…

General Relativity and Quantum Cosmology · Physics 2013-02-25 Ahmed Farag Ali , A. Tawfik

f(R) gravity is one of the simplest generalizations of general relativity, which may explain the accelerated cosmic expansion without introducing a cosmological constant. Transformed into the Einstein frame, a new scalar degree of freedom…

General Relativity and Quantum Cosmology · Physics 2015-05-04 Kazufumi Takahashi , Jun'ichi Yokoyama

This thesis studies modified theories of gravity from a geometric viewpoint. We review the motivations for considering alternatives to General Relativity and cover the mathematical foundations of gravitational theories in Riemannian and…

General Relativity and Quantum Cosmology · Physics 2024-01-24 Erik Jensko

Prior change is discussed in observational constraints studies of nonlocally modified gravity. In the latter, a model characterized by a modification of the form $\sim m^2 R\Box^{-2}R$ to the Einstein-Hilbert action was compared against the…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Yves Dirian

Torsion gravity is a natural extension to Einstein gravity in the presence of the fermion matter sources. In this paper we adopt Wald's covariant method of Noether charge to construct the quasi-local energy of the Einstein-Cartan-fermion…

High Energy Physics - Theory · Physics 2017-09-06 Sheng-Lan Ko , Feng-Li Lin , Bo Ning