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Related papers: Testing modified gravity with globular cluster vel…

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The MOdified Gravity (MOG) theory of J. Moffat assumes a massive vector particle which causes a repulsive contribution to the tensor gravitation. For the galaxy cluster A1689 new data for the X-ray gas and the strong lensing properties are…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Theodorus M. Nieuwenhuizen , Andrea Morandi , Marceau Limousin

A relativistic modified gravity (MOG) theory leads to a self-consistent, stable gravity theory that can describe the solar system, galaxy and clusters of galaxies data and cosmology.

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

(Abridged) Dynamical friction can be used to distinguish Newtonian gravity and modified Newtonian dynamics (MOND) because it works differently in these frameworks. This concept, however, has yet to be explored very much with MOND. Previous…

Astrophysics of Galaxies · Physics 2021-09-29 Michal Bílek , Hongsheng Zhao , Benoit Famaey , Oliver Müller , Pavel Kroupa , Rodrigo Ibata

We apply the weak field approximation limit of the covariant Scalar-Tensor-Vector Gravity (STVG) theory, so-called MOdified gravity (MOG), to the dynamics of clusters of galaxies by using only baryonic matter. The MOG effective…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 J. W. Moffat , S. Rahvar

The nonsymmetric gravitational theory predicts an acceleration law that modifies the Newtonian law of attraction between particles. For weak fields a fit to the flat rotation curves of galaxies is obtained in terms of the mass…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. W. Moffat

Modified Newtonian dynamics (Mond) has had considerable success in describing motions in galaxies. It uses a single force which falls off inversely with the distance at large distances and inversely with the square of the distance at…

Astrophysics of Galaxies · Physics 2015-06-18 Peter Rastall

We investigate gravitational lensing in the context of the MOG modified theory of gravity. Using a formulation of the theory with no adjustable or fitted parameters, we present the MOG equations of motion for slow, nonrelativistic test…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 J. W. Moffat , S. Rahvar , V. T. Toth

The theoretical basis of dark energy remains unknown and could signify a need to modify the laws of gravity on cosmological scales. In this study we investigate how the clustering and motions of galaxies can be used as probes of modified…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-10 Stuart Lyall , Chris Blake , Ryan Turner , Rossana Ruggeri , Hans Winther

We apply our scalar-tensor-vector (STVG) modified gravity theory (MOG) to calculate the infall velocities of the two clusters constituting the Bullet Cluster 1E0657-06. In the absence of an applicable two-body solution to the MOG field…

General Relativity and Quantum Cosmology · Physics 2010-05-18 J. W. Moffat , V. T. Toth

The equation of motion in the generally covariant modified gravity (MOG) theory leads for weak gravitational fields and the non-relativistic limit to a modification of the Newtonian gravitational acceleration law, expressed in terms of two…

Astrophysics of Galaxies · Physics 2016-10-31 J. W. Moffat

The rotation curves of low surface brightness galaxies provide a unique data set with which to test alternative theories of gravitation over a large dynamic range in size, mass, surface density, and acceleration. Many clearly fail,…

Astrophysics · Physics 2015-06-24 Stacy McGaugh , Erwin de Blok

Modified Newtonian dynamics (MOND) is an empirically motivated modification of Newtonian gravity or inertia suggested by Milgrom as an alternative to cosmic dark matter. The basic idea is that at accelerations below a0 ~ 10^{-8} cm/s^2 ~…

Astrophysics · Physics 2009-11-07 Robert H. Sanders , Stacy S. McGaugh

Wide binary stars are used to test the modified gravity called Scalar-Tensor-Vector Gravity or MOG. This theory is based on the additional gravitational degrees of freedom, the scalar field $G=G_N(1+\alpha)$, where $G_N$ is Newton's…

General Relativity and Quantum Cosmology · Physics 2024-05-31 John W. Moffat

We discuss the galaxy clustering based on thermodynamics and statistical mechanics in the expanding universe in a modified theory of gravity. The modified general relativity (MGR) is developed using the regular line element field to…

General Physics · Physics 2023-02-15 Abdul W. Khanday , Sudhaker Upadhyay , Prince A. Ganai

X-ray emitting clusters of galaxies are considered in the context of modified Newtonian dynamics (MOND). I show that self-gravitating isothermal gas spheres are not good representations of rich clusters with respect to the radial gas…

Astrophysics · Physics 2009-11-07 R. H. Sanders

Although the modified dynamics (MOND) proposed by Milgrom successfully accounts for the systematics of galaxy rotation curves and cluster dynamics without invoking dark matter, the idea remains a largely ad hoc modification of Newtonian…

Astrophysics · Physics 2009-10-28 R. H. Sanders

We investigate how different models that have been proposed for solving the dark matter problem can fit the velocity dispersion observed around elliptical galaxies, on either a small scale (~ 20kpc) with stellar tracers, such as planetary…

Astrophysics · Physics 2009-11-13 O. Tiret , F. Combes , G. W. Angus , B. Famaey , H. S. Zhao

Practically all the full-fledged MOND theories propounded to date are of the modified-gravity (MG) type: they modify only the Newtonian, Poisson action of the gravitational potential, or the general-relativistic Einstein-Hilbert action,…

Astrophysics of Galaxies · Physics 2023-11-17 Mordehai Milgrom

Despite the success of dark-matter models, unresolved issues require exploring alternatives such as modified gravity theories. In this context, we examine the compatibility of the Hyperconical Modified Gravity (HMG) with galaxy rotation…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-24 Robert Monjo

The discrepancies between recently reported experimental values of the gravitational constant were analysed within an inertia interpretation of MOND theory. According to this scenario the relative gravitational acceleration between a test…

General Relativity and Quantum Cosmology · Physics 2016-10-31 Norbert Klein