Exact multiplicity of positive solutions for degenerate concave-convex problems
摘要
We consider a degenerate p-Laplacian equation, with a reaction that exhibits the competing effects of a parametric concave term and of a sign-changing convex perturbation. Using variational tools and critical groups, we prove an existence and multiplicity result which is global in the parameter. In the process, we also prove some general results of independent interest.