Positive solutions for $(p,q)$-equations with convection and a
We consider a nonlinear Dirichlet problem driven by the
$(p,q)$-Laplacian and with a reaction which is dependent on the
gradient. We look for positive solutions and we do not assume that the
reaction is nonnegative. Using a mixture of variational and topological
methods (the “frozen variable” technique), we prove the existence of a
positive smooth solution.