Cosmological Constant as a Free Thermodynamical Variable

TL;DR

This paper proposes a model where the cosmological constant is treated as a thermodynamical variable, leading to a new equation of state and a positive lower bound depending on microscopic constituents.

Contribution

It introduces a microscopic model of a spacelike two-sphere with discrete constituents to treat the cosmological constant as a thermodynamical variable.

Findings

Derives a thermodynamical equation of state for the cosmological constant.

Shows the cosmological constant has a positive lower bound.

Connects microscopic structure to macroscopic cosmological properties.

Abstract

We consider a possibility that the cosmological constant may not be a constant, but a free thermodynamical variable. To this end we construct a microscopic model of a spacelike two-sphere just inside of the cosmological horizon of the de Sitter spacetime. In our model the spacelike two-sphere in question is assumed to consist of discrete constituents, each of them contributing to the two-sphere an area, which is in an integer times a constant. Using our model we obtain a thermodynamical equation of state for the cosmological constant. Our equation of state implies that the cosmological constant has a certain positive lower bound, which depends on the number of the constituents of the two-sphere.