Results 31 to 40 of about 4,199,505 (352)

Hermitian composition operators on Hardy-Smirnov spaces

Concrete Operators, 2017
Let Ω be an open simply connected proper subset of the complex plane and φ an analytic self map of Ω. If f is in the Hardy-Smirnov space defined on Ω, then the operator that takes f to f º φ is a composition operator.
Gunatillake Gajath
doaj   +1 more source

Approximation numbers of composition operators on Hp

Concrete Operators, 2015
give estimates for the approximation numbers of composition operators on the Hp spaces, 1 ≤ p < ∞
Li Daniel, Queffélec Hervé, Rodríguez-Piazza Luis   +2 more
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Jan Stochel, a stellar mathematician [PDF]

Opuscula Mathematica
The occasion for this survey article was the 70th birthday of Jan Stochel, professor at Jagiellonian University, former head of the Chair of Functional Analysis and a prominent member of the Kraków school of operator theory.
Sameer Chavan, Raúl Curto, Zenon Jan Jabłoński, Il Bong Jung, Mihai Putinar   +4 more
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Composite operators in QCD [PDF]

Nuclear Physics B, 1992
We give a formula for the derivatives of a correlation function of composite operators with respect to the parameters (i.e., the strong fine structure constant and the quark mass) of QCD in four-dimensional euclidean space. The formula is given as spatial integration of the operator conjugate to a parameter. The operator product of a composite operator
openaire   +2 more sources

Universal composition operators

Journal of Operator Theory, 2021
A Hilbert space operator U is called \textit{universal} (in the sense of Rota) if every Hilbert space operator is similar to a multiple of U restricted to one of its invariant subspaces. It follows that the \textit{invariant subspace problem} for Hilbert spaces is equivalent to the statement that all minimal invariant subspaces for U are one ...
Carmo, João R., Noor, S. Waleed
openaire   +2 more sources

Hypercyclic Composition Operators

Journal of Vasyl Stefanyk Precarpathian National University, 2015
In this paper we give survey of hypercyclic composition operators. In pacticular,we represent new classes of hypercyclic composition operators on the spaces of analyticfunctions
openaire   +3 more sources

The Composition operator induced by a polynomial of degree n

مجلة بغداد للعلوم, 2011
In this paper, we characterize normal composition operators induced by holomorphic self-map , when and .Moreover, we study other related classes of operators, and then we generalize these results to polynomials of degree n.
Baghdad Science Journal
doaj   +1 more source

Composition-Differentiation Operator on the Bergman Space

Pan-American Journal of Mathematics, 2023
We investigate the properties of composition-differentiation operator Dψ on the Bergman space of the unit disk L2a(D). Specifically, we characterize the properties of the reproducing kernel for the derivatives of the Bergman space functions. Moreover, we
K. O. Aloo, J. O. Bonyo, I. Okello
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Isometric multiplication operators and weighted composition operators of BMOA

Journal of Inequalities and Applications, 2021
Let u be an analytic function in the unit disk D $\mathbb{D}$ and φ be an analytic self-map of D $\mathbb{D}$ . We give characterizations of the symbols u and φ for which the multiplication operator M u $M_{u}$ and the weighted composition operator M u ,
Ligang Geng
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Absolutely summing weighted composition operators on Bloch spaces

Journal of operator theory, 2022
We characterize p -summing composition operators C ϕ ( f ) = f ◦ ϕ from a Bloch space B µ to another such space B β , where µ, β > 0 . The corresponding result on little Bloch-type spaces is also proved.
Tonie Fares, Pascal Lefèvre
semanticscholar   +1 more source