Soliton resonances for the good Boussinesq equation

Resonant multisoliton interactions in one space dimension, involving a resonance triad and an arbitrary number N of solitary waves are discussed for the good Boussinesq (GB) equation. It is shown that any of the special (regular) N-soliton solutions, which are obtained at the boundary of the regularity domain, describe one of the four basic processes (related by time reversal and/or space reversal) in the presence of (N-2) (or (N-3)) 'spectator' solitons. In contrast with the two-dimensional case (KP equation), the GB resonant vertices cannot include more than three solitary waves.