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Related papers: NGC 1052-DF2 And Modified Gravity (MOG) Without Da…

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We compare the measurement of the gravitational mass of 38 high-redshift galaxy clusters observed by Chandra using Modified Newtonian Dynamics (MOND) and standard Newtonian gravity. Our analysis confirms earlier findings that MOND cannot…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-14 Carl Blaksley , Massimiliano Bonamente

(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

An impact model of gravity designed to emulate Newton's law of gravitation is applied to the radial acceleration of disk galaxies. Based on this model (Wilhelm et al. 2013), the rotation velocity curves can be understood without the need to…

Astrophysics of Galaxies · Physics 2017-09-11 K. Wilhelm , B. N. Dwivedi

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

New measurements of the velocity dispersion of the globular cluster omega Centauri allow to trace its gravitational potential down to an acceleration of 8e-9 cm/s/s. It is found that the dispersion profile remains flat well inside the tidal…

Astrophysics · Physics 2007-05-23 Riccardo Scarpa , Gianni Marconi , Roberto Gilmozzi

The evolution of disk galaxies in modified gravity is studied by using high-resolution N-body simulations. More specifically, we use the weak field limit of two modified gravity theories, i.e., nonlocal gravity (NLG) and…

Astrophysics of Galaxies · Physics 2020-05-28 Neda Ghafourian , Mahmood Roshan , Shahram Abbassi

Different formulations of MOND predict somewhat different rotation curves for the same mass distribution. Here I consider a global attribute of the rotation curve that might provide a convenient discriminant between theories when applied to…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-27 Mordehai Milgrom

The recently claimed discovery of an ultra-diffuse galaxy lacking dark matter has important implications for alternate theories to dark matter as well as models of galaxy formation within the $\Lambda$CDM context. In this letter, we present…

Astrophysics of Galaxies · Physics 2018-11-01 Aditya Chowdhury

Scalar-Tensor-Vector Gravity (STVG), also referred as MOdified Gravity (MOG), is an alternative theory of the gravitational interaction. Its weak field approximation has been successfully used to described Solar System observations, galaxy…

General Relativity and Quantum Cosmology · Physics 2017-02-02 Federico G. Lopez Armengol , Gustavo E. Romero

Two ultra diffuse galaxies in the same group, NGC1052-DF2 and NGC1052-DF4, have been found to have little or no dark matter and to host unusually luminous globular cluster populations. Such low mass diffuse objects in a group environment…

A new class of Kuiper belt objects that lie beyond Neptune with semimajor axes greater than 250 astronomical units show orbital anomalies that have been interpreted as evidence for an undiscovered ninth planet. We show that a modified…

General Relativity and Quantum Cosmology · Physics 2023-08-25 Katherine Jones-Smith , Harsh Mathur

We present a simple model for the shape of the distribution function of galaxy peculiar velocities. We show how both nonlinear and linear theory terms combine to produce a distribution which has an approximately Gaussian core with…

Astrophysics · Physics 2009-10-31 Ravi K. Sheth , Antonaldo Diaferio

In this work, we investigate the MOdified Gravity (MOG) theory for dynamics of the universe and compare the results with the $\Lambda$CDM cosmology. We study the background cosmological properties of the MOG model and structure formation at…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-17 Zahra Davari , Sohrab Rahvar

Conformal geometry is considered within a general relativistic framework. An invariant distant for proper time is defined and a parallel displacement is applied in the distorted space-time, modifying Einstein's equation appropriately. A…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Edmund A. Chadwick , Timothy F. Hodgkinson , Graham S. McDonald

Modified Newtonian Dynamics (MOND) is a possible solution for the missing mass problem in galactic dynamics; its predictions are in good agreement with observations in the limit of weak accelerations. However, MOND does not derive from a…

Astrophysics of Galaxies · Physics 2017-01-18 Sascha Trippe

By the time, in 1937, the Swiss astronomer Zwicky measured the velocity dispersion of the Coma cluster of galaxies, astronomers somehow got acquainted with the idea that the universe is filled by some kind of dark matter. After almost a…

Astrophysics · Physics 2009-11-11 Riccardo Scarpa

Dark Matter (DM) and Modified Newtonian Dynamics (MOND) models of rotationally supported galaxies lead to curves with different geometries in $(g_{N},g_{tot})$-space ($g2$-space). Here $g_{tot}$ is the total acceleration and $g_{N}$ is the…

Astrophysics of Galaxies · Physics 2020-09-04 Jonas Petersen , Mads T. Frandsen

Dynamical mass discrepancies in galaxies have two possible explanations: the existence of large amounts of dark matter or the breakdown of Newtonian gravity. True dark matter halos of galaxies could differ in several respects from apparent…

Astrophysics · Physics 2007-05-23 J. A. Sellwood , A. Kosowsky

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

Based on Newtonian dynamics, observations show that the luminous masses of astrophysical objects that are the size of a galaxy or larger are not enough to generate the measured motions which they supposedly determine. This is typically…

General Relativity and Quantum Cosmology · Physics 2016-04-22 Chung-Ming Ko