Magneto-optical/ferromagnetic-material computation: Backlund transformations, bilinear forms and N solitons for a generalized (3+1)-dimensional variable-coefficient modified Kadomtsev-Petviashvili system

Of current interest, magneto-optics deals with the phenomena associated with magnetic effects on matter as it emits light, having the potential applications in computer data-storage and waveguides, while ferromagnetic materials are the ones displaying ferromagnetism, such as the various forms of iron, steel, cobalt, nickel, and their alloys. In this paper, in magneto-optics, ferromagnetism, fluid mechanics and plasma physics, we investigate a generalized (3+1)-dimensional variable-coefficient modified Kadomtsev-Petviashvili system for the electromagnetic waves in a ferromagnetic material, or water waves, or dust-acoustic/ion-acoustic/dustion-acoustic waves in a plasma. Special cases of the system in those fields are listed out, such as one special case in magneto-optics, which describes the electromagnetic waves in an isotropic charge-free ferromagnetic thin film with the potential application in magneto-optic recording. With symbolic computation, we work out (1) two sets of the variable-coefficient-dependent auto-Backlund transformations along with some solitonic features, (2) the variable-coefficient-dependent bilinear forms with the Hirota method and (3) two branches of the variable-coefficient-dependent N-soliton solutions with N being a positive integer. Relevant constraints on the variable coefficients are presented. (C) 2020 Elsevier Ltd. All rights reserved.