Semigroup estimates and noncoercive boundary value problems
The authors give conditions guaranteeing that irregular boundary value problems of the second order for elliptic differential-operator equations with a parameter in an interval are coercive with a defect. They also prove compactness of the resolvents and completeness of the system of the root functions. Applications are given to irregular boundary value problems for second- order elliptic equations.
elliptic differential-operator equations
scientific article; zbMATH DE number 1394458