Axions, Monopoles and Cosmic String

TL;DR

This paper explores the interactions between axion domain walls, monopoles, and cosmic strings, revealing phenomena like monopole transformation into dyons, chiral states at membranes, and CP violation effects in string-wall intersections.

Contribution

It introduces new insights into monopole and string interactions with axion structures, including monopole bag formation and CP violation mechanisms.

Findings

Monopoles become dyons when passing through axion domain walls.

Cosmic strings intersecting axion walls induce maximal CP violation.

String interactions can lead to baryon charge nonconservation.

Abstract

We are discussing some aspects of the magnetic monopoles and cosmic strings interactions with axion domain walss and membranes. The monopole moving through an axion domain wall is transformed into a monopole bag - the state with a dyon quantum number, but smaller mass. In the case of an axion membrane the passing monopole excites the chiral charged state at the membrane boundary. It will be shown that if cosmic string intersects an axion domain wall there will be $\theta = \pi$, i.e. maximal $CP$-violation inside the string. Strings carrying the flux of the $Z$-boson field become the sources of the baryon charge nonconservation. The symbiosis of the two pictures - monopole passing through an axion domain wall and string intersecting it - is the case of the interaction between an axion domain wall and a Nambu electroweak string carrying $SU(2)_{L}$ monopoles at the ends.