Non-Newtonian polytropic filtration systems with nonlinear boundary conditions

This article deals with the global existence and the blow-up of non-Newtonian polytropic filtration systems with nonlinear boundary conditions. Necessary and sufficient conditions on the global existence of all positive (weak) solutions are obtained by constructing various upper and lower solutions. Mathematics Subject Classification (2000) 35K50, 35K55, 35K65