Displaying similar documents to “The division method for subspectra of self-adjoint differential vector-operators.”

On the spectral properties of translation operators in one-dimensional tubes

Wojciech Hyb (1991)

Annales Polonici Mathematici

Similarity:

We study the spectral properties of some group of unitary operators in the Hilbert space of square Lebesgue integrable holomorphic functions on a one-dimensional tube (see formula (1)). Applying the Genchev transform ([2], [5]) we prove that this group has continuous simple spectrum (Theorem 4) and that the projection-valued measure for this group has a very explicit form (Theorem 5).

Functions of operators and their commutators in perturbation theory

Yu. Farforovskaya (1994)

Banach Center Publications

Similarity:

This paper shows some directions of perturbation theory for Lipschitz functions of selfadjoint and normal operators, without giving precise proofs. Some of the ideas discussed are explained informally or for the finite-dimensional case. Several unsolved problems are mentioned.

Representations and Positive Definite Functions on Hypergroups

Nasr-Isfahani, A. (1999)

Serdica Mathematical Journal

Similarity:

Some relationships between representations of a hypergroup X, its algebras, and positive definite functions on X are studied. Also, various types of convergence of positive definite functions on X are discussed.