Correspondence of I- and Q-balls as Non-relativistic Condensates

TL;DR

This paper demonstrates that I-balls (oscillons) can be understood as projections of non-relativistic Q-balls within a complex scalar field framework, with their stability linked to U(1) symmetry conservation.

Contribution

It establishes a theoretical connection between I-balls and Q-balls in non-relativistic regimes, clarifying stability and longevity through U(1) symmetry considerations.

Findings

I-balls are projections of Q-balls in non-relativistic limits

U(1) symmetry ensures I-ball stability under non-relativistic conditions

Longevity of I-balls relates to U(1) charge violation processes

Abstract

If a real scalar field is dominated by non-relativistic modes, then it approximately conserves its particle number and obeys an equation that governs a complex scalar field theory with a conserved global U(1) symmetry. From this fact, it is shown that the I-ball (oscillon) can be naturally understood as a projection (e.g., real part) of the non-relativistic Q-ball solution. In particular, we clarify that the stability of the I-ball is guaranteed by the U(1) symmetry in the corresponding complex scalar field theory as long as the non-relativistic condition holds. We also discuss the longevity of I-ball from the perspective of the complex scalar field in terms of U(1) charge violating processes.