Global time-analytic strong solutions for a class of 3-wave kinetic equations

We study a class of 3-wave kinetic equations arising in wave turbulence theory, with regularized kernels.

For radial, nonnegative initial data, we construct an exact global-in-time strong solution which remains nonnegative and is analytic with respect to time.

The proof combines a careful analysis of the resonant interaction surfaces with a time power-series construction and a continuation argument based on the conservation of the energy moment.