Topological Influence between Monopoles and Vortices: a Possible Resolution of the Monopole Problem

TL;DR

This paper proposes that the interaction between monopoles and Alice strings can lead to monopole annihilation, potentially resolving the monopole problem by changing the topological charge classification from  to .

Contribution

It introduces a topological influence mechanism where Alice strings cause monopole pairs to annihilate, altering the monopole charge classification in certain grand unified theories.

Findings

Monopoles can annihilate in pairs due to Alice string influence.

Monopole charge classification changes from  to  in the presence of Alice strings.

This mechanism offers a possible resolution to the monopole problem.

Abstract

Grand unified theories of fundamental forces predict that magnetic monopoles are inevitable in the Universe because the second homotopy group of the order parameter manifold is $\mathbb{Z}$. We point out that monopoles can annihilate in pairs due to an influence of Alice strings. As a consequence, a monopole charge is charactarized by $\mathbb{Z}_2$ rather than $\mathbb{Z}$ if the Universe can accommodate Alice strings, which is the case of certain grand unified theories.