Topological degree for a class of elliptic operators in ${\mathbb R}^n$
Cristelle Barillon, Vitaly A Volpert · Topological Methods in Nonlinear Analysis · 1999
A class of elliptic operators in ${\mathbb R}^n$ is considered. It is proved that the operators are Fredholm and proper. The topological degree is constructed. Existence of solutions for a reaction-diffusion system is studied.