A novel (2+1)-dimensional Sawada-Kotera type system: multisoliton solution and variable separation solution

A novel (2+1)-dimensional system of the Sawada-Kotera type is considered. The existence of three-soliton and four-soliton solutions with wave number constraints is confirmed. Other interesting solutions, such as the long-range interaction between a line soliton and a y-periodic soliton, are also presented based on the Hirota formalism. By extending the multilinear variable separation approach to the fifth-order nonlinear evolution equation, various localized excitations are introduced, including solitoff, dromion, and an instanton excited by three resonant dromions. In addition to these localized excitations, the general fusion or fission type N-solitary wave solution is obtained, the Y-shaped resonant soliton and the T-type resonant soliton interaction in shallow water are graphically explored.