Dwarf Galaxies, MOND, and Relativistic Gravitation

Abstract

MOND is a phenomenological modification of Newton's law of gravitation which reproduces the dynamics of galaxies, without the need for additional dark matter. This paper reviews the basics of MOND and its application to dwarf galaxies. MOND is generally successful at reproducing stellar velocity dispersions in the Milky Way's classical dwarf ellipticals, for reasonable values of the stellar mass-to-light ratio of the galaxies; two discrepantly high mass-to-light ratios may be explained by tidal effects. Recent observations also show MOND describes tidal dwarf galaxies, which form in complex dynamical environments. The application of MOND to galaxy clusters, where it fails to reproduce observed gas temperatures, is also reviewed. Relativistic theories containing MOND in the non-relativistic limit have now been formulated; they all contain new dynamical fields, which may serve as additional sources of gravitation that could reconcile cluster observations with MOND. Certain limits of these theories can also give the accelerating expansion of the Universe. The standard dark matter cosmology boasts numerous manifest triumphs; however, alternatives should also be pursued as long as outstanding observational issues remain unresolved, including the empirical successes of MOND on galaxy scales and the phenomenology of dark energy.

9 pages, contribution to the Dwarf Galaxies special issue of Advances in Astronomy

References in corpus (22)

• A direct empirical proof of the existence of dark matter
• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• A common mass scale for satellite galaxies of the Milky Way
• Revealing the properties of dark matter in the merging cluster MACSJ0025.4-1222
• On the Proof of Dark Matter, the Law of Gravity and the Mass of Neutrinos
• From Tidal Dwarf Galaxies to Satellite Galaxies
• Tidal dwarf galaxies as a test of fundamental physics
• Confrontation of MOND with the rotation curves of early-type disc galaxies
• Are sterile neutrinos consistent with clusters, the CMB and MOND?
• Dwarf Spheroidals in MOND
• Testing Fundamental Physics with Distant Star Clusters: Analysis of Observational Data on Palomar 14
• Satellite Galaxies and Fossil Groups in the Millennium Simulation
• MOND and the mass discrepancies in tidal dwarf galaxies
• The collision velocity of the bullet cluster in conventional and modified dynamics
• MOND plus classical neutrinos not enough for cluster lensing
• Equilibrium configurations of 11eV sterile neutrinos in MONDian galaxy clusters
• MOND rotation curves of very low mass spiral galaxies
• Testing gravity with motion of satellites around galaxies: Newtonian gravity against Modified Newtonian Dynamics
• The necessity of dark matter in MOND within galactic scales
• The relation between stellar mass and weak lensing signal around galaxies: Implications for MOND
• Modified gravity, Dark Energy and MOND
• Milgrom Relation Models for Spiral Galaxies from Two-Dimensional Velocity Maps

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• Palatini Approach to Modified Gravity: f(R) Theories and Beyond
• Implications for dwarf spheroidal mass content from interloper removal
• A Monte Carlo analysis of the velocity dispersion of the globular cluster Palomar 14
• What do gas-rich galaxies actually tell us about modified Newtonian dynamics?
• The Atacama Cosmology Telescope: A Test of the Gravitational Force Law on Cosmological Scales Using the Kinematic Sunyaev-Zeldovich Effect
• Non-linear energy conservation theorem in the framework of Special Relativity