A doubly nonlinear elliptic problem with variable exponents, homogeneous Neumann boundary conditions and generalized logistic source
We study a class of doubly nonlinear elliptic problems with variable exponents and homogeneous Neumann boundary conditions arising in the time discretization, by Rothe's method, of an associated doubly nonlinear parabolic problem. A main feature of the present work is that the structural assumptions imposed on the source term are weakened: in particular, no local Lipschitz continuity with respect to the state variable is required. Instead, we work under a weaker monotonicity-type assumption involving the source term and the nonlinear function $b$. A key ingredient in the analysis is the continuity of the associated Nemytskii operators between suitable variable-exponent Lebesgue spaces.