Q-ball stress stability criterion in the $U(1)$ gauged scalar theories

Abstract: We study the canonical energy-momentum tensor of the spherically symmetric $U(1)$ gauged Q-ball configurations in the two-component Fridberg-Lee-Sirlin-Maxwell model, and in the one-component scalar model with a sixtic potential. We evaluate the distributions of the corresponding shear forces and pressure and study the stability criteria for these solutions. It is shown that the electrostatic repulsion may destabilize the $U(1)$ gauged Q-balls. However, in the limiting case of the Fridberg-Lee-Sirlin-Maxwell model with a long ranged real scalar component, the gauged Q-balls always remain stable.