Go with the Flow, Average Holographic Universe

TL;DR

This paper explores the holographic nature of gravity, linking thermodynamics and quantum space-time, and suggests that Einstein's equations can be derived from entropy maximization principles, offering insights into the cosmological constant problem.

Contribution

It presents a novel thermodynamic derivation of gravitational equations emphasizing the holographic principle and addresses the cosmological constant issue.

Findings

Gravity emerges from entropy flow in space-time.

Einstein's equations can be derived from entropy extremization.

The approach naturally resolves the cosmological constant problem.

Abstract

Gravity is a macroscopic manifestation of a microscopic quantum theory of space-time, just as the theories of elasticity and hydrodynamics are the macroscopic manifestation of the underlying quantum theory of atoms. The connection of gravitation and thermodynamics is long and deep. The observation that space-time has a temperature for accelerating observers and horizons is direct evidence that there are underlying microscopic degrees of freedom. The equipartition of energy, meaning of temperature, in these modes leads one to anticipate that there is also an entropy associated. When this entropy is maximized on a volume of space-time, then one retrieves the metric of space-time (i.e. the equations of gravity, e.g. GR). Since the metric satisfies the extremum in entropy on the volume, then the volume integral of the entropy can readily be converted to surface integral, via Gauss's Theorem. This surface integral is simply an integral of the macroscopic entropy flow producing the mean entropy holographic principle. This approach also has the added value that it naturally dispenses with the cosmological constant/vacuum energy problem in gravity except perhaps for second order quantum effects on the mean surface entropy.