Results 31 to 40 of about 633 (85)
The invariant subspace problem for absolutely p-summing operators in Krein spaces
Let 1 ...
G. Wanjala
semanticscholar +2 more sources
Strongly Lipschitz up-Nuclear Operators
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
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
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
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
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
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
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
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
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