Topological degree for elliptic operators in unbounded cylinders
The authors construct a topological degree for elliptic operators \[ A(u) = a(x)\Delta u + \sum_{i=1}^m b_i(x)\frac{\partial u}{\partial x_i} + F(x,u) +K(u),\quad \Lambda u = \left.\left(\alpha\frac{\partial u}{\partial\nu} + \beta(x)u\right) \right|_{\partial\Omega}, \] in an unbounded cylinder \(\Omega\). Here \(u=\{u_1,\ldots,u_p\}\), \(F\) is a vector-valued function and \(K\) is a finite-dimensional operator included in view of applications: the traveling waves investigation. Standard degree theory is constructed in weighted Hölder spaces.
semilinear elliptic operators in unbounded cylinders
scientific article; zbMATH DE number 1493613