Results 31 to 40 of about 633 (85)

Strongly Lipschitz up-Nuclear Operators

open access: yesMoroccan Journal of Pure and Applied Analysis, 2019
In this paper, we introduce the notion of strongly Lipschitz up-nuclear operators. Among other results, we prove an analog of the factorization theorem for these classes and characterize their conjugates.
Belacel Amar, Bey Khedidja
doaj   +1 more source

On k-quasi-M-hyponormal operators

open access: yes, 2013
In this present article we introduce a new class of operators which we will be called the class of k -quasi-M -hyponormal operators that includes hyponormal an M -hyponormal operators.
S. Mécheri
semanticscholar   +1 more source

Geometric properties of composition operators belonging to Schatten classes

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 26, Issue 4, Page 239-248, 2001., 2001
We investigate the connection between the geometry of the image domain of an analytic function mapping the unit disk into itself and the membership of the composition operator induced by this function in the Schatten classes. The purpose is to provide solutions to Lotto′s conjectures and show a new compact composition operator which is not in any of ...
Yongsheng Zhu
wiley   +1 more source

Putnam‐Fuglede theorem and the range‐kernel orthogonality of derivations

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 27, Issue 9, Page 573-582, 2001., 2001
Let ℬ(H) denote the algebra of operators on a Hilbert space H into itself. Let d = δ or Δ, where δAB : ℬ(H) → ℬ(H) is the generalized derivation δAB(S) = AS − SB and ΔAB : ℬ(H) → ℬ(H) is the elementary operator ΔAB(S) = ASB − S. Given A, B, S ∈ ℬ(H), we say that the pair (A, B) has the property PF(d(S)) if dAB(S) = 0 implies dA∗B∗(S)=0.
B. P. Duggal
wiley   +1 more source

A bound for the Hilbert-Schmidt norm of generalized commutators of nonself-adjoint operators

open access: yes, 2017
Let A, à and B be bounded linear operators in a Hilbert space, and f (z) be a function regular on the convex hull of the union of the spectra of A and à . Let SN2 be the ideal of Hilbert-Schmidt operators.
M. Gil'
semanticscholar   +1 more source

(r, p)‐absolutely summing operators on the space C (T, X) and applications

open access: yesAbstract and Applied Analysis, Volume 6, Issue 5, Page 309-315, 2001., 2001
We give necessary and sufficient conditions for an operator on the space C (T, X) to be (r, p)‐absolutely summing. Also we prove that the injective tensor product of an integral operator and an (r, p)‐absolutely summing operator is an (r, p)‐absolutely summing operator.
Dumitru Popa
wiley   +1 more source

Bounded sets in the range of an X∗∗‐valued measure with bounded variation

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 23, Issue 1, Page 21-30, 2000., 2000
Let X be a Banach space and A ⊂ X an absolutely convex, closed, and bounded set. We give some sufficient and necessary conditions in order that A lies in the range of a measure valued in the bidual space X∗∗ and having bounded variation. Among other results, we prove that X∗ is a G.
B. Marchena, C. Piñeiro
wiley   +1 more source

A NOTE ON P-SYMMETRIC OPERATORS

open access: yes, 2016
Let L(H) denote the algebra of operators on a complex infinite dimensional Hilbert space H into itself. In this paper, we study the class of operators A ∈ L(H) which satisfy the following property, AT = TA implies AT ∗ = T ∗A for all T ∈ C1(H) (trace ...
S. Bouali   +3 more
semanticscholar   +1 more source

Monotone and convex H*‐algebra valued functions

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 3, Page 473-479, 1996., 1995
Classical theorems about monotone and convex functions are generalized to the case of H*‐algebra valued functions. Also there are new examples of a vector measure.
Parfeny P. Saworotnow
wiley   +1 more source

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