  Non-topological solitons are localized classical field configurations
stabilized by a Noether charge. Friedberg, Lee, and Sirlin proposed a simple
renormalizable soliton model in their seminal 1976 paper, consisting of a
complex scalar field that carries the Noether charge and a real-scalar
mediator. We revisit this model, point out commonalities and differences with
Q-ball solitons, and provide analytic approximations to the underlying
differential equations.
