Modified Entropic Force

TL;DR

This paper proposes a modification to the entropic force formula inspired by the Debye model, extending Newtonian gravity to weak fields, and explains cosmic acceleration without dark energy.

Contribution

It introduces a Debye-based modification to entropic force, providing a new approach to explain cosmic acceleration without dark energy.

Findings

Debye acceleration g_D=10^{-15} N/kg

Modified entropic force approximates Newtonian gravity in solar system

Cosmic acceleration explained without dark energy

Abstract

The theory of statistical thermodynamics tells us the equipartition law of energy does not hold in the limit of very low temperatures. It is found the Debye model is very successful in explaining the experimental results for most of the solid objects. Motivated by this fact, we modify the entropic force formula which is proposed very recently. Since the Unruh temperature is proportional to the strength of gravitational field, so the modified entropic force formula is an extension of the Newtonian gravity to weak field. On the contrary, General Relativity extends Newtonian gravity to strong field case. Corresponding to Debye temperature, there exists a Debye acceleration g_D. It is found the Debye acceleration is g_D=10^{-15}N kg^{-1}. This acceleration is very much smaller than the gravitational acceleration 10^{-4}N kg^{-1} which is felt by the Neptune and the gravitational acceleration 10^{-10}N kg^{-1} felt by the Sun. Therefore, the modified entropic force can be very well approximated by the Newtonian gravity in the solar system and in the Galaxy. With this Debye acceleration, we find the current cosmic speeding up can be explained without invoking any kind of dark energy.