“…When ρ = const, system (1.1) becomes the incompressible Hall-MHD system, which has received many studies, see [1,4,5,6,13,14,17,36,37,38]. When divu = 0, system (1.1) becomes the density-dependent Hall-MHD system, which has been investigated by many authors, and for more details, see [12,18].…”