Q-branes

TL;DR

This paper explores non-abelian Q-ball solutions in string theory, specifically within dielectric D-brane systems, revealing their properties, charge characteristics, and potential implications in extra-dimensional models.

Contribution

It demonstrates the existence of non-abelian Q-balls on dielectric D-branes and analyzes their behavior in extra-dimensional contexts, including charge and energy properties.

Findings

Non-abelian Q-balls exist on dielectric D-branes.

Q-balls carry Kaluza-Klein charge and have a tower of states.

Exact solutions are found for models with logarithmic potentials.

Abstract

Non-topological solitons (Q-balls) are discussed in some stringy settings. Our main result is that the dielectric D-brane system of Myers admits non-abelian Q-ball solutions on their world-volume, in which $N$ D$p$-branes relax to the standard dielectric form outside the Q-ball, but assume a more diffuse configuration at its centre. We also consider how Q-balls behave in the bulk of extra-dimensional theories, or on wrapped branes. We demonstrate that they carry Kaluza-Klein charge and possess a corresponding Kaluza-Klein tower of states just as normal particles, and we discuss surface energy effects by finding exact Q-ball solutions in models with a specific logarithmic potential.