Dark photon -- Assisted Primordial Magnetogenesis

TL;DR

This paper proposes a minimal mechanism involving dark photons coupled with standard photons to generate cosmic magnetic fields, overcoming limitations of previous models and potentially explaining unresolved cosmic mysteries.

Contribution

It introduces a novel dark photon coupling mechanism for primordial magnetogenesis that avoids strong-coupling and backreaction issues present in earlier theories.

Findings

Coupling dark photons with standard photons can produce adequate magnetic fields.

The mechanism circumvents the strong-coupling and backreaction problems.

It offers potential insights into unresolved cosmic mysteries.

Abstract

Magnetic fields observed across cosmic scales are difficult to explain within conventional physics. A primordial origin is, thus, often assumed. While a nonminimal coupling of the inflaton with the electromagnetic field could theoretically generate magnetic fields of about $10^{-13}$ G, this approach faces significant issues, including strong-coupling and backreaction problems. ``Dark photons", arising naturally in hidden-sector extensions of the Standard Model, provide a well-motivated framework for addressing various cosmic as well as particle physics issues. We demonstrate that coupling dark photons with standard ones can result in adequate magnetogenesis without the limitations of existing models. This minimal mechanism may also provide insights into unresolved cosmic mysteries.