BPS Magnetic Monopole Bags

TL;DR

This paper investigates spherical configurations of many BPS magnetic monopoles, revealing two extreme regimes—Abelian and non-Abelian bags—with distinct internal structures and field distributions.

Contribution

It introduces and characterizes the concepts of Abelian and non-Abelian monopole bags, detailing their field configurations and spatial arrangements in the large N limit.

Findings

Abelian bags have Higgs zeros on a sphere with confined gauge fields.

Non-Abelian bags have all Higgs zeros at the origin with a shell structure.

Both regimes feature a thin shell at radius R_cr separating different field behaviors.

Abstract

We explore the characteristics of spherical bags made of large numbers of BPS magnetic monopoles. There are two extreme limits. In the Abelian bag, $N$ zeros of the Higgs field are arranged in a quasiregular lattice on a sphere of radius $R_{\rm cr} \sim N/v$, where $v$ is the Higgs vacuum expectation value. The massive gauge fields of the theory are largely confined to a thin shell at this radius that separates an interior with almost vanishing magnetic and Higgs fields from an exterior region with long-range Coulomb magnetic and Higgs fields. In the other limiting case, which we term a non-Abelian bag, the $N$ zeros of the Higgs field are all the origin, but there is again a thin shell of radius $R_{\rm cr}$. In this case the region enclosed by this shell can be viewed as a large monopole core, with small Higgs field but nontrivial massive and massless gauge fields.