Field theory models for variable cosmological constant

TL;DR

This paper introduces models where a spontaneously broken discrete symmetry explains the small parameters in scalar field and four-form field solutions to the cosmological constant problem, linking them to particle physics frameworks.

Contribution

It presents a new class of models with small parameters arising from symmetry breaking and demonstrates their equivalence and integration into standard model extensions.

Findings

Small parameters explained by symmetry breaking

Equivalence between scalar and four-form models shown

Models embedded into left-right symmetric extensions

Abstract

Anthropic solutions to the cosmological constant problem require seemingly unnatural scalar field potentials with a very small slope or domain walls (branes) with a very small coupling to a four-form field. Here we introduce a class of models in which the smallness of the corresponding parameters can be attributed to a spontaneously broken discrete symmetry. We also demonstrate the equivalence of scalar field and four-form models. Finally, we show how our models can be naturally embedded into a left-right extension of the standard model.