M-quasi-hyponormal composition operators.

Suri, Pushpa R.; Singh, N.

Displaying similar documents to “M-quasi-hyponormal composition operators.”

Some results on composition operators on $ℓ^{2}$ .

Singh, R.K., Gupta, D.K., Komal, B.S. (1979)

International Journal of Mathematics and Mathematical Sciences

Similarity:

On Quasi-Normality of Two-Sided Multiplication

Amouch, M. (2009)

Serdica Mathematical Journal

Similarity:

2000 Mathematics Subject Classification: 47B47, 47B10, 47A30. In this note, we characterize quasi-normality of two-sided multiplication, restricted to a norm ideal and we extend this result, to an important class which contains all quasi-normal operators. Also we give some applications of this result.

Linear maps preserving quasi-commutativity

Heydar Radjavi, Peter Šemrl (2008)

Studia Mathematica

Similarity:

Let X and Y be Banach spaces and ℬ(X) and ℬ(Y) the algebras of all bounded linear operators on X and Y, respectively. We say that A,B ∈ ℬ(X) quasi-commute if there exists a nonzero scalar ω such that AB = ωBA. We characterize bijective linear maps ϕ : ℬ(X) → ℬ(Y) preserving quasi-commutativity. In fact, such a characterization can be proved for much more general algebras. In the finite-dimensional case the same result can be obtained without the bijectivity assumption.

A quasi-affine transform of an unbounded operator

Schôichi Ôta (1995)

Studia Mathematica

Similarity:

Some results on quasi-affinity for bounded operators are extended to unbounded ones and normal extensions of an unbounded operator are discussed in connection with quasi-affinity.

Quasi-convex functions and quasi-monotone operators.

Levin, Vladimir L. (1995)

Journal of Convex Analysis

Similarity:

A remark on the range of elementary operators

Said Bouali, Youssef Bouhafsi (2010)

Czechoslovak Mathematical Journal

Similarity:

Let $L (H)$ denote the algebra of all bounded linear operators on a separable infinite dimensional complex Hilbert space $H$ into itself. Given $A \in L (H)$ , we define the elementary operator $Δ_{A} : L (H) ⟶ L (H)$ by $Δ_{A} (X) = A X A - X$ . In this paper we study the class of operators $A \in L (H)$ which have the following property: $A T A = T$ implies $A T^{*} A = T^{*}$ for all trace class operators $T \in C_{1} (H)$ . Such operators are termed generalized quasi-adjoints. The main result is the equivalence between this character and the fact that the ultraweak closure of the range of $Δ_{A}$ is closed...

A property of quasi-complements

Robert H. Lohman (1974)

Colloquium Mathematicae

Similarity:

A generalization of Ćirić quasi-contraction

T. K. Pal, M. Maiti (1977)

Matematički Vesnik

Similarity:

On the geometric definition of the quasi-conformality

Cabiria Andreian Cazacu (1981)

Annales Polonici Mathematici

Similarity:

Quasi-inverses of morphisms

Roman Sikorski (1974)

Fundamenta Mathematicae

Similarity:

A Fuglede-Putnam theorem modulo the Hilbert-Schmidt class for almost normal operators with finite modulus of Hilbert-Schmidt quasi-triangularity

Vasile Lauric (2016)

Concrete Operators

Similarity:

We extend the Fuglede-Putnam theorem modulo the Hilbert-Schmidt class to almost normal operators with finite Hilbert-Schmidt modulus of quasi-triangularity.