Nonlinear boundary conditions for elliptic equations
Pablo Amster, Maria Cristina Mariani, Osvaldo Méndez · Repositorio Digital Institucional de la Universidad de Buenos Aires (Universidad de Buenos Aires) · 2005
This work is devoted to the study of the elliptic equation $Delta u = f(x,u)$ in a bounded domain $Omegasubset mathbb{R}^n$ with a nonlinear boundary condition. We obtain various existence results applying coincidence degree theory and the method of upper and lower solutions.