An extension of Leray-Schauder degree and applications to nonlinear wave equations
Juha Berkovits, Vesa Mustonen · Differential and Integral Equations · 1990
In this paper we introduce a construction of the classical topological degree for a class of mappings of monotone type motivated by the periodic Dirichlet problem for the semilinear wave equationUsing homotopy arguments of the degree theory we derive existence theorems for the abstract setting which can be applied to the problem (SWE).