Cosmic magnetic fields and dark energy in extended electromagnetism

TL;DR

This paper proposes an extended electromagnetism theory where a new scalar state, generated during inflation, can explain dark energy and produce large-scale magnetic fields, linking cosmology and fundamental physics.

Contribution

It introduces a novel extension of electromagnetism with a physical gauge fixing term, generating a scalar state that accounts for dark energy and cosmic magnetic fields.

Findings

Scalar state can produce an effective cosmological constant matching observations.

The model generates large-scale magnetic fields coherent with the current Hubble horizon.

Inflation at the electroweak scale suffices to produce the observed dark energy.

Abstract

We discuss an extended version of electromagnetism in which the usual gauge fixing term is promoted into a physical contribution that introduces a new scalar state in the theory. This new state can be generated from vacuum quantum fluctuations during an inflationary era and, on super-Hubble scales, gives rise to an effective cosmological constant. The value of such a cosmological constant coincides with the one inferred from observations as long as inflation took place at the electroweak scale. On the other hand, the new state also generates an effective electric charge density on sub-Hubble scales that produces both vorticity and magnetic fields with coherent lengths as large as the present Hubble horizon.