Understanding the Quantized Angular Momentum of Rotating Q-balls

TL;DR

This paper derives the properties of rotating Q-balls, revealing their quantized angular momentum and characteristic angular velocity, through analytical and numerical methods, enhancing understanding of their role in cosmology.

Contribution

The paper provides a derivation of the scalar field configurations for rotating Q-balls, offering new analytical approximations and insights into their angular momentum and velocity.

Findings

Analytical approximations match numerical results.

Rotating Q-balls exhibit quantized angular momentum.

Method to compute characteristic angular velocity.

Abstract

Non-topological solitons, such as Q-balls, may contribute to the cosmological dark matter. The formation and evolution of Q-balls in the early universe requires an understanding of solitons with nonzero angular momentum. We derive (rather than assume) the schematic form of the scalar field configurations that produce rotating Q-balls, which produce their well known quantized angular momentum. This analysis leads to additional insight into the properties of these rotating solitons, including a method for computing their characteristic angular velocity. By considering rotating solitons in two spatial dimensions, we investigate these attributes concretely. We develop analytical approximations for the solitons and their defining quantities. We show that they agree with numerical results and exhibit the general properties of rotating solitons.