Q-balls are non-topological solitons stabilized by a conserved charge — they exist because a global U(1) symmetry prevents their decay. Oscillons are long-lived, approximately periodic field configurations with no conserved charge — they should decay but persist for thousands of oscillation periods. The two objects look different: one is stabilized by symmetry, the other by something else.
Xie, Amin, and Hertzberg show the relationship persists in non-canonical kinetic theories. In models where the kinetic term is a general function of the standard kinetic energy (K-field theories), Q-balls and oscillons coexist with modified profiles. The oscillon is the real-field shadow of the Q-ball — the Q-ball's charge-carrying phase rotation is replaced by amplitude oscillation, but the spatial profile and stability mechanisms are closely related.
In phi^2 potentials — the simplest possible mass term with no self-interaction — the non-canonical kinetic term provides the nonlinearity needed for localization. Standard phi^2 theory with canonical kinetic term produces no localized solutions. The K-field modification creates effective self-interaction through the kinetic sector, enabling both Q-balls and oscillons in a theory that would otherwise support neither.
The novel profile structures in K-field theories belong to distinct universality classes from their canonical counterparts. The oscillon profiles are not perturbative deformations of standard oscillons — they have qualitatively different radial structure, controlled by the specific form of the kinetic function.
Two types of localized field configurations, one with charge and one without, persisting as relatives across different theories. The family resemblance survives the change of kinetic structure.