Global shift symmetry and vacuum energy of matter fields

TL;DR

This paper develops a model where a global shift symmetry in matter fields is spontaneously broken, leading to a Goldstone boson that becomes an inflaton, with gravity explicitly breaking the symmetry.

Contribution

It introduces a novel framework linking shift symmetry breaking, Goldstone bosons, and inflation within matter-gravity interactions.

Findings

Goldstone boson acts as an inflaton.

Gravity explicitly breaks the shift symmetry.

Model allows arbitrary cosmological constant shifts.

Abstract

We construct the model incorporating both an arbitrary shift of cosmological constant and Goldstone boson corresponding to the spontaneous breaking down the global shift symmetry in the matter action. The gravity breaks down the symmetry explicitly and transforms the Goldstone boson to the inflaton field.