Results 71 to 80 of about 137 (130)
Essentially hyponormal operators with essential spectrum contained in a circle
Le Matematiche, 2009 In this paper two results are given . It is proved that if the essential spectrum σ(π(T)) of the bounded hyponormal operator T is contained in a circle, then T is essentially normal operator. Based on this result it is proved that if T∈ L(H) with ind T =
Shquipe I. Lohaj, Muhib R. Lohaj
doaj
Spectral mapping of hyponormal or semi-hyponormal operators
Journal of Mathematical Analysis and Applications, 1981 For TE P(R’), we write ( T( = (PT)‘12. In this paper, when we consider a semi-hyponormal operator T, we &ways assume that the operator U in the polar decomposition T = U 1 TI is unitary, for the sake of simplicity. Let E be a bounded closed set in the real line R 1, and M(E) be the class of all stricly monotone increasing continuous function on E ...
openaire +1 more source
A remark on λ-interwining hyponormal operators
Le Matematiche, 2014 We extend a result concerning λ-commuting normal operators with empty point spectrum. More precisely, we prove that for a hyponormal operator T with empty point spectrum for which there exists a Hilbert-Schmidt operator K such that TK = λKT + μK for some
Vasile Lauric
doaj
The Fuglede-Putnam theorem for
Journal of Inequalities and Applications, 2006 We show that if is a -quasihyponormal operator and is a -hyponormal operator, and if , where is a quasiaffinity (i.e., a one-one map having dense range), then is a normal and moreover is unitarily equivalent to .
Kim In Hyoun
doaj
An invariant for certain operator algebras. [PDF]
Proc Natl Acad Sci U S A, 1974 Carey RW, Pincus JD.
europepmc +1 more source
The spectrum of seminormal operators. [PDF]
Proc Natl Acad Sci U S A, 1971 Pincus JD.
europepmc +1 more source
Powers of class
Journal of Inequalities and Applications, 2002 An operator belongs to class for and if and only if if and only if where is generalized Aluthge transformation of , that is, . Class was introduced by Ito as a generalization of -hyponormality which was introduced by Aluthge and Wang.
Yanagida Masahiro
doaj