Eternal inflation and a thermodynamic treatment of Einstein's equations

TL;DR

This paper explores the thermodynamic nature of Einstein's equations in the context of eternal inflation, proposing a first law for quasi-de Sitter space and linking fluctuations to thermodynamic regimes, with parallels to black hole evaporation.

Contribution

It develops a thermodynamic first law for quasi-de Sitter space applicable to eternal inflation and demonstrates the regime where fluctuations align with thermodynamic principles.

Findings

Fluctuations in eternal inflation fit within the thermodynamic regime.

A thermodynamic first law for quasi-de Sitter space is formulated.

Parallels are drawn between eternal inflation and black hole evaporation.

Abstract

In pursuing the intriguing resemblance of the Einstein equations to thermodynamic equations, most sharply seen in systems possessing horizons, we suggest that eternal inflation of the stochastic type may be a fruitful phenomenon to explore. We develop a thermodynamic first law for quasi-de Sitter space, valid on the horizon of a single observer's Hubble patch and explore consistancy with previous proposals for horizons of various types in dynamic and static situations. We use this framework to demonstrate that for the local observer fluctuations of the type necessary for stochastic eternal inflation fall within the regime where the thermodynamic approach is believed to apply. This scenario is interesting because of suggestive parallels to black hole evaporation.