Existência de soluções para problemas elípticos não lineares com condições de Neumann e Dirichlet-Neumann via metodo variacional

The objective of this master's dissertation is to study, under specific assumptions, the existence and nonexistence of weak, nontrivial, and nonnegative solutions to a nonlinear elliptic problem subject, initially, to Neumann boundary conditions and, subsequently, to mixed Neumann–Dirichlet boundary