TITLE:
Modified Newtonian Dynamics as an Entropic Force
AUTHORS:
Diego A. Carranza, Sergio Mendoza
KEYWORDS:
Alternative Theories of Gravity, Modified Newtonian Dynamics, Classical Black Holes, Entropy, Thermodynamics of Black Holes
JOURNAL NAME:
Journal of Modern Physics,
Vol.6 No.6,
May
25,
2015
ABSTRACT: Under natural assumptions on the
thermodynamic properties of space and time with the holo-graphic principle, we
reproduce a MOND-like behaviour of gravity on particular scales of mass and
length, where Newtonian gravity requires a modification or extension if no dark
matter component is introduced in the description of gravitational phenomena.
The result is directly obtained with the assumption that a fundamental constant
of nature with dimensions of acceleration needs to be introduced into
gravitational interactions. This in turn allows for modifications or extensions
of the equipartion law and/or the holographic principle. In other words,
MOND-like phenomenology can be reproduced when appropriate generalised concepts
at the thermodynamical level of space and/or at the holographic principle are
introduced. Thermodynamical modifications are reflected in extensions to the
equipartition law which occur when the temperature of the system drops below a
critical value, equals to Unruh’s temperature evaluated at the acceleration
constant scale introduced for the description of the gravitational phenomena.
Our calculations extend the ones by [1] in which Newtonian gravity is shown to
be an emergent phenomenon, and together with it reinforces the idea that
gravity at all scales is emergent.