Cauchy matrix approach to novel extended semi-discrete KP-type systems

Abstract: Two novel extended semi-discrete KP-type systems, namely partial differential-difference systems with one continuous and two discrete variables, are investigated. Introducing an arbitrary function into the Cauchy matrix function or the plane wave factor allows the implementation of extended integrable systems within the Cauchy matrix approach. We introduce the bilinear D\delta2KP system, the extended D\delta2pKP, D\delta2pmKP, and D\delta2SKP systems, all of which are based on the Cauchy matrix approach. This results in a diversity of solutions for these extended systems as contrasted to the usual multiple soliton solutions.