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Related papers: Modified General Relativity and dark matter

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The accelerated expansion of the universe implies the existence of an energy contribution known as dark energy. Associated with the cosmological constant in the standard model of cosmology, the nature of this dark energy is still unknown.…

General Relativity and Quantum Cosmology · Physics 2022-03-01 Ekim Taylan Hanımeli , Isaac Tutusaus , Brahim Lamine , Alain Blanchard

Astrophysical data analysis of the weak-field predictions support the claim that modified gravity (MOG) theories provide a self-consistent, scale-invariant, universal description of galaxy rotation curves, without the need of non-baryonic…

Astrophysics of Galaxies · Physics 2009-08-09 J. R. Brownstein

We show how Conformal Gravity (CG) has to satisfy a fine-tuning condition to describe the rotation curves of disk galaxies without the aid of dark matter. Interpreting CG as a gauge natural theory yields conservation laws and their…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-11 M. C. Campigotto , A. Diaferio , L. Fatibene

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

In this work we use generalized deformed gauge groups for investigation of symmetry of general relativity (GR). GR is formulated in generalized reference frames, which are represented by (anholonomic in general case) affine frame fields.…

General Relativity and Quantum Cosmology · Physics 2020-06-09 S. E. Samokhvalov

Any connection between dark matter and extra dimensions can be cognizably evinced from the associated effective energy-momentum tensor. In order to investigate and test such relationship, a higher dimensional spacetime endowed with a…

General Relativity and Quantum Cosmology · Physics 2013-07-17 C. H. Coimbra-Araujo , Roldao da Rocha

The Energy Problem (EP) in General Relativity (GR) is analyzed in the context of GR's axiomatic inconsistencies. EP is classified according to its local and global aspects. The local aspects of the EP include noncovariance of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alexander Poltorak

In General Relativity, the constraint equation relating metric and density perturbations is inherently nonlinear, leading to an effective non-Gaussianity in the dark matter density field on large scales - even if the primordial metric…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-31 Nicola Bartolo , Daniele Bertacca , Marco Bruni , Kazuya Koyama , Roy Maartens , Sabino Matarrese , Misao Sasaki , Licia Verde , David Wands

The reconstruction scheme is developed for modified $f(R)$ gravity with realistic matter (dark matter, baryons, radiation). Two versions of such theory are constructed: the first one describes the sequence of radiation and matter…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We study the non-relativistic expansion of general relativity coupled to matter. This is done by expanding the metric and matter fields analytically in powers of $1/c^2$ where $c$ is the speed of light. In order to perform this expansion it…

General Relativity and Quantum Cosmology · Physics 2020-07-15 Dennis Hansen , Jelle Hartong , Niels A. Obers

In this manuscript, we provide a comprehensive study of gravitational lensing by dark compact objects predicted by a Modified Gravity (MOG) based on the Scalar-Vector-Tensor action, and the aim is to analyze new insights into the nature of…

General Relativity and Quantum Cosmology · Physics 2025-03-07 Nagina Rehman , Zoe C. S. Chan , Mubasher Jamil , Mustapha Azreg-Aïnou

We consider the linearized nonsymmetric theory of gravitation (NGT) within the background of an expanding universe and near a Schwarzschild mass. We show that the theory always develops instabilities unless the linearized nonsymmetric…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Tomas Janssen , Tomislav Prokopec

We incorporate the effect of non-local gravitational self-energy to obtain a neutral, non-singular spacetime geometry. This is achieved by using a non-local gravitational theory inspired by T-duality, where particle mass is not point-like…

General Relativity and Quantum Cosmology · Physics 2026-05-04 Kimet Jusufi , Douglas Singleton

We propose an alternative theory of gravity which assumes that background geometry of the Universe is fixed four dimensional Euclidean space and gravity is a vector field $A_k$ in this space which breaks the Euclidean symmetry. Direction of…

General Relativity and Quantum Cosmology · Physics 2017-11-21 Anatoly A. Svidzinsky

A scalar-tensor theory of gravity is formulated in which $G$ and particle masses are allowed to vary. The theory yields a globally static cosmological model with no evolutionary timescales, no cosmological coincidences, and no flatness and…

General Physics · Physics 2015-10-01 Meir Shimon

There is now strong observational evidence that the expansion of the universe is accelerating. The standard explanation invokes an unknown "dark energy" component. But such scenarios are faced with serious theoretical problems, which has…

Astrophysics · Physics 2008-11-26 Martin Kunz , Domenico Sapone

We discuss theoretical formalisms concerning with experimental verification of General Relativity (GR). Non-metric generalizations of GR are considered and a system of postulates is formulated for metric-affine and Finsler gravitational…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. Alexandrov , I. B. Vavilova , V. I. Zhdanov

Modified Gravity (MOG) has been used successfully to explain the rotation curves of galaxies, the motion of galaxy clusters, the Bullet Cluster, and cosmological observations without the use of dark matter or Einstein's cosmological…

General Relativity and Quantum Cosmology · Physics 2009-04-04 J. W. Moffat , V. T. Toth

We show that it is possible to obtain a picture of equilibrium thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density $f(R, \phi, X)$, where…

General Relativity and Quantum Cosmology · Physics 2010-10-12 Kazuharu Bamba , Chao-Qiang Geng , Shinji Tsujikawa

We show that General Relativity (GR) with cosmological constant may be formulated as a rather simple constrained SO(D-1,2) (or SO(D,1))-Yang-Mills (YM) theory. Furthermore, the spin connections of the Cartan-Einstein formulation for GR…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Botta Cantcheff
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