A Fixed Point Theorem In Menger Spaces
We extend the Fuglede-Putnam theorem modulo the Hilbert-Schmidt class to almost normal operators with finite Hilbert-Schmidt modulus of quasi-triangularity.
For a holomorphic function ψ defined on a sector we give a condition implying the identity where A is a sectorial operator on a Banach space X. This yields all common descriptions of the real interpolation spaces for sectorial operators and allows easy proofs of the moment inequalities and reiteration results for fractional powers.
The paper generalizes the instruction, suggested by B. Sz.-Nagy and C. Foias, for operatorfunction induced by the Cauchy problem A unitary dilatation for is constructed in the present paper. then a translational model for the family is presented using a model construction scheme, suggested by Zolotarev, V., [3]. Finally, we derive a discrete functional model of family and operator applying the Laguerre transform where are Laguerre polynomials [6, 7]. We show that the Laguerre transform...