Radiative corrections and instability of large Q-Balls

TL;DR

This paper investigates the stability of large Q-balls interacting with fermions, revealing a maximal charge for stability and exploring the origins of additional instabilities in theories with flat directions.

Contribution

It provides new insights into the classical stability limits of large Q-balls and analyzes the effects of fermion interactions and flat directions on their stability.

Findings

Maximal stable charge for Q-balls is approximately 1/g^4.

Additional instabilities arise in models with flat directions.

Strategies to mitigate these instabilities are discussed.

Abstract

We discuss stability of Q-balls interacting with fermions in theory with small coupling constant g. We argue that for configurations with large global U(1)-charge Q the problem of classical stability becomes more subtle. For example, in model with flat direction there is maximal value of charge for stable solutions with Q~1/g^4. We study origin of additional instability and discuss possible ways to avoid it.