scholarly journals Alternatives to Dark Matter (?)

2004 ◽  
Vol 220 ◽  
pp. 17-26 ◽  
Author(s):  
Anthony Aguirre
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
General Idea ◽  
Galactic Dynamics ◽  
Modified Newtonian Dynamics ◽  
Newtonian Dynamics ◽  
Visible Matter

It has long been known that Newtonian dynamics applied to the visible matter in galaxies and clusters does not correctly describe the dynamics of those systems. While this is generally taken as evidence for dark matter it is in principle possible that instead Newtonian dynamics (and with it General Relativity) breaks down in these systems. Indeed there have been a number of proposals as to how standard gravitational dynamics might be modified so as to correctly explain galactic dynamics without dark matter. I will review this general idea (but focus on “MOdified Newtonian Dynamics”, or “MOND”), and discuss a number of ways alternatives to dark matter can be tested and, in many cases, ruled out.

scholarly journals QUANTUM GRAVITY AND DARK MATTER

2011 ◽  
Vol 20 (14) ◽  
pp. 2887-2893 ◽  
Author(s):  
CHIU MAN HO ◽  
DJORDJE MINIC ◽  
Y. JACK NG
Keyword(s):  
Dark Matter ◽  
Quantum Gravity ◽  
Cold Dark Matter ◽  
Galactic Dynamics ◽  
Modified Newtonian Dynamics ◽  
Newtonian Dynamics ◽  
Salient Features

We propose a connection between global physics and local galactic dynamics via quantum gravity. The salient features of cold dark matter (CDM) and modified Newtonian dynamics (MOND) are combined into a unified scheme by introducing the concept of MONDian dark matter which behaves like CDM at cluster and cosmological scales but emulates MOND at the galactic scale.

scholarly journals Gravitational Lensing and Modified Newtonian Dynamics

2001 ◽  
Vol 18 (2) ◽  
pp. 189-191
Author(s):  
Daniel J. Mortlock ◽  
Edwin L. Turner
Keyword(s):  
General Relativity ◽  
Gravitational Lensing ◽  
A Priori ◽  
Massive Particle ◽  
Speed Of Light ◽  
Modified Newtonian Dynamics ◽  
Newtonian Dynamics ◽  
Visible Matter ◽  
Relativistic Extension ◽  
The Universe

AbstractGravitational lensing is most often used as a tool to investigate the distribution of (dark) matter in the universe, but, if the mass distribution is known a priori, it becomes, at least in principle, a powerful probe of gravity itself. Lensing observations are a more powerful tool than dynamical measurements because they allow measurements of the gravitational field far away from visible matter. For example, modified Newtonian dynamics (MOND) has no relativistic extension, and so makes no firm lensing predictions, but galaxy–galaxy lensing data can be used to empirically constrain the deflection law of a MONDian point-mass. The implied MONDian lensing formalism is consistent with general relativity, in so far as the deflection experienced by a photon is twice that experienced by a massive particle moving at the speed of light. With the deflection law in place and no invisible matter, MOND can be tested wherever lensing is observed.

GALACTIC DYNAMICS VIA GENERAL RELATIVITY AND THE EXOTIC DARK MATTER ENIGMA

2006 ◽  
Vol 21 (28) ◽  
pp. 2133-2142 ◽  
Author(s):  
F. I. COOPERSTOCK ◽  
S. TIEU
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Velocity Dispersion ◽  
Symmetry Plane ◽  
Galactic Dynamics ◽  
Galactic Rotation ◽  
Matter Distribution ◽  
Rotation Curves ◽  
Newtonian Dynamics ◽  
Observational Test

General relativity supersedes Newtonian dynamics in the analysis of galactic rotation and eliminates the need for vast halos of exotic dark matter. We present new results to complete the global picture of galactic models which indicate that we can model relatively modest mass accumulations surrounding galaxies with mass concentrations roughly contained within the contours of the extended disk. An observational test of the extent of any external matter distribution is shown to derive from the velocity dispersion of rotation curves in planes parallel to the galactic symmetry plane. We reply to recent critics of our work.

scholarly journals Necessity of Dark Matter in Modified Newtonian Dynamics within Galactic Scales

2008 ◽  
Vol 100 (3) ◽  
Author(s):  
Ignacio Ferreras ◽  
Mairi Sakellariadou ◽  
Muhammad Furqaan Yusaf
Keyword(s):  
Dark Matter ◽  
Modified Newtonian Dynamics ◽  
Newtonian Dynamics

scholarly journals How can rainbow gravity affect gravitational force?

2016 ◽  
Vol 25 (14) ◽  
pp. 1650101 ◽  
Author(s):  
Akram Sadat Sefiedgar
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Force ◽  
Entropic Force ◽  
Recent Proposal ◽  
Modified Newtonian Dynamics ◽  
Corrected Entropy ◽  
Newtonian Dynamics ◽  
Area Law ◽  
Einstein’S General Relativity

According to Verlinde’s recent proposal, the gravity is originally an entropic force. In this paper, we obtain the corrections to the entropy-area law of black holes within rainbow gravity. The corrected entropy-area law leads to the modifications of the number of bits [Formula: see text]. Inspired by Verlinde’s argument on the entropic force, and using the modified number of bits, we can investigate the effects of rainbow gravity on the modified Newtonian dynamics, Newton’s law of gravitation, and Einstein’s general relativity in entropic force approach.

scholarly journals The Modified Newtonian Dynamics as an Alternative to Hidden Matter

1987 ◽  
Vol 117 ◽  
pp. 319-333
Author(s):  
Mordehai Milgrom ◽  
Jacob Bekenstein
Keyword(s):  
Dark Matter ◽  
Main Body ◽  
Modified Newtonian Dynamics ◽  
Newtonian Dynamics ◽  
Nonrelativistic Theory ◽  
The Masses ◽  
Modified Dynamics

The mass discrepancy, which has led to the notion of dark matter may, in fact, be due to a breakdown of the Newtonian laws which are used to determine the masses of galactic systems. We describe a nonrelativistic theory which departs from Newton's in the limit of small accelerations. When one uses the modified dynamics to deduce gravitational masses, the need to invoke large quantities of dark matter disappears. We outline the theory and give criteria for deciding which systems are expected to exhibit marked departures from Newtonian behaviour. The main body of the talk is a succinct description of the major predictions of the theory regarding dynamics within galaxies.

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