The aim of this book is to present a systematic treatment of the theory of unbounded linear operators in normed linear (not necessarily Hilbert) spaces with applications to differential equations. Except for the last chapter, the material is quite self-contained. The reader is assumed to be familiar with metric spaces and real variable theory.
The book could be introduced in a course in functional analysis, particularly when linear operators are studied. By considering differential or integro-differential equations from the point of view of operator theory, the material may also be useful to those concerned with the more applied aspects of analysis.