The cosmological constant problem: a user's guide

TL;DR

This paper explores the cosmological constant problem by examining the limits of general relativity at low energies, proposing a new mass scale and potential equivalence principle violations.

Contribution

It relates the breakdown of general relativity at low energies to the observed cosmological constant, suggesting a specific mass scale and possible equivalence principle violations.

Findings

Proposes a mass scale of approximately 10^{-3} eV related to the cosmological constant.

Suggests potential violation of the equivalence principle at about 10^{-14} level.

Links the validity of general relativity to the observed value of the cosmological constant.

Abstract

We discuss the validity of general relativity at low-energy and relate the threshold below which the theory breaks down with the observed value of the cosmological constant. This suggests the existence of a mass scale of ${\cal O}(10^{-3}) eV$ and a putative violation of the equivalence principle at about $10^{-14}$ level.