Cosmology-Independent Constraints on Irreducible Magnetic Monopole Background

TL;DR

This paper introduces a new, cosmology-independent method to constrain magnetic monopoles by analyzing their impact on galactic magnetic fields, providing novel bounds from cosmic ray interactions with the interstellar medium.

Contribution

It generalizes Parker bounds to extended monopole spectra and sets first constraints on monopole effects in Andromeda, independent of cosmological assumptions.

Findings

Constraints on monopoles from galactic magnetic field disruption

First bounds on Andromeda's magnetic fields affected by monopoles

Estimation of magnetic dipole moment constraints from cosmic rays

Abstract

We present a novel mechanism for the irreducible production of magnetic monopoles from interactions of cosmic rays and interstellar medium (ISM). Resulting monopoles drain energy from galactic magnetic fields, disrupting their formation and sustainability. We generalize conventional Parker bounds to monopoles with extended energy spectrum and, considering cosmic ray ISM monopole production, set novel constraints from disruption of Milky Way Galactic magnetic fields and their seeds. Further, we set first constraints on disruption of galactic magnetic fields and their seeds of Andromeda galaxy, with results being competitive with distinct existing bounds. Unlike Parker limits of previous works that relied on cosmological monopoles, our constraints are independent of cosmological monopole production or their primordial abundance. Besides, we estimate new constraints on dipole magnetic moments generated from cosmic ray ISM interactions. We discuss implications for monopoles with generalized magnetic charges.