A new set and new relations of multiple soliton solutions of (2 + 1)-dimensional Sawada–Kotera equation

A new transformation v=4(lnf)xx that can formulate a quintic linear equation and pair of Hirota’s bilinear equations for the (2 + 1)-dimensional Sawada–Kotera (2DSK) Eq. (1) or u=4(lnf)x 2DSK (2) is reported firstly, which enables one to obtain set multiple soliton solutions equation. They are not special cases known solitons. The results presented in this paper show only possesses two sets solutions, but also has relation between them square fn n-soliton solution u=4(lnfn)x be obtained from singularity limit f2n 2n-soliton u=2(lnf2n)x by using dual combination rules singular method. This property unusual first found so far us. Also, it establishes connection because solved equations, SK under case u=2(lnf)x, other KdV (1 does possess property. As another example, (3 nonlinear partial differential possessing however bearing studied.