The Leray-Schauder approach to the degree theory for \((S_+)\)-perturbations of maximal monotone operators in separable reflexive Banach spaces
The paper develops the classical topological degree theory of Leray and Schauder to a degree theory for operators of type \(T+f\) in separable reflexive Banach spaces, where \(T\) is a strongly quasibounded and maximal operator, while \(f\) is a demicontinuous, bounded and of type \((S_+)\) perturbation. Certain basic homotopy properties are shown to hold. An extension of this degree theory to strongly quasibounded (but not necessarily bounded) perturbations \(f\) is also presented.
scientific article; zbMATH DE number 5551978
scientific article