General Theory of Unbounded Operators in Hilbert Spaces
Yu. M. Berezansky, Zinovij G. Sheftel, Georgij F. Us · Birkhäuser Basel eBooks · 1996
Most of the operators encountered in mathematical physics are unbounded. As a rule, they are constructed by using the operation of differentiation. In this chapter, we present general principles of the theory of unbounded operators in complex Hilbert spaces.