Runaway Domain Wall and Space-time Varying alpha

TL;DR

This paper proposes a model involving a runaway domain wall that explains observed spatial and temporal variations in the fine structure constant alpha, aligning with current data and offering testable predictions for future experiments.

Contribution

It introduces a novel scalar field model with a runaway potential that accounts for both spatial and temporal variations of alpha.

Findings

Model explains observed alpha variations

Consistent with current cosmological data

Predicts testable effects on the equivalence principle

Abstract

Recently spatial as well as temporal variations of the fine structure constant alpha have been reported. We show that a "runaway domain wall", which arises for the scalar field potential without minima, can account for such variations simultaneously. The time variation is induced by a runaway potential and the spatial variation is induced by the formation of a domain wall. The model is consistent with the current cosmological data and can be tested by the future experiments to test the equivalence principle.