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Related papers: Modified Gravity (MOG), Cosmology and Black Holes

200 papers

The distinction between modified gravity and quintessence or dynamical dark energy is difficult. Many models of modified gravity are equivalent to models of coupled quintessence by virtue of variable transformations. This makes an…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 C. Wetterich

We extend a recent work on weak field first order light deflection in the MOdified Gravity (MOG) by comprehensively analyzing the actual observables in gravitational lensing both in the weak and strong field regime. The static spherically…

General Relativity and Quantum Cosmology · Physics 2023-11-17 R. N. Izmailov , R. Kh. Karimov , E. R. Zhdanov , K. K. Nandi

In the past few decades, various versions of modified gravity theories were proposed to mimic the effect of dark matter. Compared with the conventional Newtonian or relativistic dynamics, these theories contain some extra apparent force…

General Relativity and Quantum Cosmology · Physics 2023-02-01 Man Ho Chan , Chak Man Lee

A complete canonical formulation of general covariance makes it possible to construct new modified theories of gravity that are not of higher-curvature form, as shown here in a spherically symmetric setting. The usual uniqueness theorems…

General Relativity and Quantum Cosmology · Physics 2024-04-10 Martin Bojowald , Erick I. Duque

The static vacuum spherically symmetric solutions in massive gravity are obtained both analytically and numerically. The solutions depend on two parameters (integration constants): the mass M (or, equivalently, the Schwarzschild radius),…

General Relativity and Quantum Cosmology · Physics 2011-06-10 Michael V. Bebronne , Peter G. Tinyakov

Emergent modified gravity presents a new set of generally covariant gravitational theories in which the space-time metric is not directly given by one of the fundamental fields. A metric compatible with the modified dynamics of gravity is…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Martin Bojowald , Erick I. Duque

Recently, the static spherically symmetric solution of the gravitational field equations have been found in theories describing massive graviton with spontaneous breaking of the Lorentz invariance. These solutions, which show off two…

General Relativity and Quantum Cosmology · Physics 2009-05-07 Michael V. Bebronne

This note includes results of a study of stationary spherically symmetric ``dark holes'', objects merging central black holes and peripheral scalar graviton dark haloes arising in the framework of the modified gravity -- the quartet-metric,…

General Relativity and Quantum Cosmology · Physics 2025-07-15 Yu. F. Pirogov , O. V. Zenin

A conformal coupling of the metric in the Jordan frame to the energy-momentum tensor, screens the scalar field gravitational coupling strength $G$ in modified gravity (MOG). The scalar field acquires a mass which depends on the local matter…

General Relativity and Quantum Cosmology · Physics 2014-10-14 J. W. Moffat

In the present work, we review some general aspects of modified gravity theories, investigating mathematical and physical properties and, more specifically, the feature of viable and realistic models able to reproduce the dark energy epoch…

General Relativity and Quantum Cosmology · Physics 2013-10-16 Ratbay Myrzakulov , Lorenzo Sebastiani , Sergio Zerbini

Based on the scalar-tensor-vector modified gravitational theory, a modified gravity Schwarzschild black hole solution has been given in the existing literature. Such a black hole spacetime is obtained through the inclusion of a modified…

General Relativity and Quantum Cosmology · Physics 2022-06-10 Daqi Yang , Wenfu Cao , Naying Zhou , Hongxing Zhang , Wenfang Liu , Xin Wu

We study the global gravitational stability of a gaseous self-gravitating Maclaurin disk in the absence of a halo. Further, we replace Newtonian gravity with the specific Modified gravity theory known as MOG in the relevant literature. MOG…

Astrophysics of Galaxies · Physics 2016-12-14 Mahmood Roshan , Shahram Abbassi , Habib G. Khosroshahi

The prediction of spacetime singularities, regions of infinite curvature where classical physics breaks down, is one of the most profound challenges in General Relativity (GR). In particular, black hole solutions such as the Schwarzschild…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Jose Pinedo Soto

Scalar Tensor Vector Gravity(STVG) is one of modified gravity theories developed by John Moffat(2005). MOG is abbreviated name for this theory.It can explain a galactic rotation curve and the structure formation without dark matter. It can…

Astrophysics of Galaxies · Physics 2012-02-21 Takayuki Suzuki

The paper deals with a modified theory of gravity and the cosmological consequences. Instead of concerning the field equations directly, we modify a conformally-related and equivalent equation, such that a spontaneous symmetry breaking at…

General Physics · Physics 2020-01-23 Christian Henke

Globular clusters (GCs) in the Milky Way have characteristic velocity dispersions that are consistent with the predictions of Newtonian gravity, and may be at odds with Modified Newtonian Dynamics (MOND). We discuss a modified gravity (MOG)…

Astrophysics · Physics 2008-06-14 J. W. Moffat , V. T. Toth

Modified Gravity (MOG) and Non-Local Gravity (NLG) are two alternative theories to General Relativity. They are able to explain the rotation curves of spiral galaxies and clusters of galaxies without including dark matter (Moffat & Rahvar…

Astrophysics of Galaxies · Physics 2017-11-09 M. H. Zhoolideh Haghighi , S. Rahvar

A non-singular, static spherically symmetric solution to the nonsymmetric gravitational and electromagnetic theory field equations is derived, which depends on the four parameters m, l^2, Q and s, where m is the mass, Q is the electric…

General Relativity and Quantum Cosmology · Physics 2008-11-26 N. J. Cornish , J. W. Moffat

General Relativity receives quantum corrections relevant at macroscopic distance scales and near event horizons. These arise from the conformal scalar degrees of freedom in the extended effective field theory of gravity generated by the…

General Relativity and Quantum Cosmology · Physics 2012-09-25 Emil Mottola

Here, cosmology is obtained from the variable gravitational constant $ G \propto \phi^{-2}$ with $ \phi(x) $ being a scalar and its fluctuations around the ground state. The gravitational action contains Einstein-Hilbert like term with…

General Relativity and Quantum Cosmology · Physics 2008-09-19 S. K. Srivastava