Gravity and/is Thermodynamics

TL;DR

This paper proposes a thermodynamic interpretation of gravity by restoring symmetry in the Lagrangian, leading to Einstein's general relativity and offering insights into the cosmological constant and quantum spacetime structure.

Contribution

It introduces a novel approach to gravity as a thermodynamic limit of atomic spacetime, naturally deriving Einstein's equations and connecting quantum spacetime properties to cosmology.

Findings

Gravity symmetry restored by adding a constant to the Lagrangian.

Derivation of Einstein's general relativity from thermodynamic principles.

Determination of the cosmological constant value.

Abstract

The equations of motion describing all physical systems, except gravity, remain invariant if a constant is added to the Lagrangian. In the conventional approach, gravitational theories break this symmetry exhibited by all other physical systems. Restoring this symmetry to gravity and demanding that gravitational field equations should also remain invariant under the addition of a constant to a Lagrangian, leads to the interpretation of gravity as the thermodynamic limit of the kinetic theory of atoms of space. This approach selects, in a very natural fashion, Einstein's general relativity in $d=4$. Developing this paradigm at a deeper level, one can obtain the distribution function for the atoms of space and connect it up with the thermodynamic description of spacetime. This extension relies on a curious fact that the quantum spacetime endows each event with a finite area but zero volume. This approach allows us determine the numerical value of the cosmological constant and suggests a new perspective on cosmology.