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Related papers: Nonlocal Gravity: Modified Poisson's Equation

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We extensively study the ultraviolet quantum properties of a nonlocal action for gravity nonminimally coupled to matter. The theory unifies matter and gravity in an action principle such that all the classical solutions of Einstein's theory…

High Energy Physics - Theory · Physics 2024-11-26 Gianluca Calcagni , Breno L. Giacchini , Leonardo Modesto , Tibério de Paula Netto , Lesław Rachwał

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

Theoretical differences in the growth of structure offer the possibility that we might distinguish between modified gravity theories of dark energy and \LambdaCDM. A significant impediment to applying current and prospective large scale…

Astrophysics · Physics 2008-11-26 Istvan Laszlo , Rachel Bean

The peculiarities of the inverse square law of Newtonian gravity in standard Big Bang Cosmology are discussed. It is shown that the incorporation of an additive term to Newtonian gravitation, as the inverse Yukawa-like field, allows remove…

General Relativity and Quantum Cosmology · Physics 2021-12-28 Nelson Falcon

We describe and analyze nonlocal integro-differential equations with classical local boundary conditions. The interaction kernel of the nonlocal operator has horizon parameter dependent on position in the domain, and vanishes as the…

Analysis of PDEs · Mathematics 2023-01-10 James M. Scott , Qiang Du

Mimetic gravity is a modified theory of gravity which is able to incorporate dark matter into the underlying geometry of space-time by isolating the conformal degree of freedom. The theory has been studied extensively in the cosmological…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Leonid Sarieddine

We introduce a technique to automatically convert local boundary conditions into nonlocal volume constraints for nonlocal Poisson's and peridynamic models. The proposed strategy is based on the approximation of nonlocal Dirichlet or Neumann…

Numerical Analysis · Mathematics 2021-07-12 Marta D'Elia , Yue Yu

We summarize the present state of research on the darkon fuid as a model for the dark sector of the Universe. Nonrelativistic massless particles are introduced as a realization of the Galilei group in an enlarged phase space. The additional…

General Relativity and Quantum Cosmology · Physics 2016-11-04 P. C. Stichel , W. J. Zakrzewski

It has been suggested that Einstein's theory of General Relativity can be modified to accomodate mismatches between the gravitational field and luminous matter on a wide range of scales. Covariant theories of modified gravity generically…

Astrophysics · Physics 2009-03-31 P. G Ferreira , C. Skordis , C. Zunckel

Is Newton's gravity sufficient to handle the weakly nonlinear evolution stages of the cosmic large-scale structures? Here we resolve the issue by analytically deriving the density and velocity power spectra to the second order in the…

Astrophysics · Physics 2008-11-26 Hyerim Noh , Jai-chan Hwang

General N=(1,1) dilaton supergravity in two dimensions allows a background independent exact quantization of the geometric part, if these theories are formulated as specific graded Poisson-sigma models. The strategy developed for the…

High Energy Physics - Theory · Physics 2009-11-10 L. Bergamin , D. Grumiller , W. Kummer

Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation that has been constructed in close analogy with the nonlocal electrodynamics of media. According to NLG, what appears as dark matter in…

Astrophysics of Galaxies · Physics 2022-07-21 Mahmood Roshan , Bahram Mashhoon

In General Relativity, the issue of defining the gravitational energy contained in a given spatial region is still unresolved, except for particular cases of localized objects where the asymptotic flatness holds for a given spacetime. In…

General Relativity and Quantum Cosmology · Physics 2023-06-06 Salvatore Capozziello , Maurizio Capriolo , Gaetano Lambiase

For (2+2)-dimensional nonholonomic distributions, the physical information contained into a spacetime (pseudo) Riemannian metric can be encoded equivalently into new types of geometric structures and linear connections constructed as…

General Relativity and Quantum Cosmology · Physics 2010-04-08 Sergiu I. Vacaru

We discuss the linearization of Einstein equations in the presence of a cosmological constant, by expanding the solution for the metric around a flat Minkowski space-time. We demonstrate that one can find consistent solutions to the…

General Relativity and Quantum Cosmology · Physics 2010-04-14 Jose Bernabeu , Catalina Espinoza , Nick E. Mavromatos

In this study, the effects of the generalized uncertainty principle on the theory of gravity are analyzed. Inspired by Verlinde's entropic gravity approach and using the modified Unruh temperature, the generalized Einstein field equations…

High Energy Physics - Theory · Physics 2019-08-02 Salih Kibaroğlu

We show that results of a simple dynamical gedanken experiment interpreted according to standard Newton's gravitational theory, may reveal that three-dimensional space is curved. The experiment may be used to reconstruct the curved geometry…

General Relativity and Quantum Cosmology · Physics 2014-12-16 M. A. Abramowicz , G. F. R. Ellis J. Horak , M. Wielgus

Occurrence of spacetime singularities is one of the peculiar features of Einstein gravity, signalling limitation on probing short distances in spacetime. This alludes to the existence of a fundamental length scale in nature. On contrary,…

General Relativity and Quantum Cosmology · Physics 2020-12-21 Omar El-Refy , Syed Masood , Li-Gang Wang , Ahmed Farag Ali

We propose a phenomenological approach to the cosmological constant problem based on generally covariant non-local and acausal modifications of four-dimensional gravity at enormous distances. The effective Newton constant becomes very small…

High Energy Physics - Theory · Physics 2007-05-23 Nima Arkani-Hamed , Savas Dimopoulos , Gia Dvali , Gregory Gabadadze

Schwarzschild's 'interior solution' is a space-time metric that satisfies Einstein's gravitational field equations with a source term that Einstein created on the basis of an unjustified identification of the conceptually distinct notions…

General Relativity and Quantum Cosmology · Physics 2012-10-18 Homer G. Ellis
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