On a Li–Stević integral-type operators between different weighted Bloch-type spaces.
On an integral-type operator from Zygmund-type spaces to mixed-norm spaces on the unit ball.
On convexity of composition and multiplication operators on weighted Hardy spaces.
On operators Cauchy dual to 2-hyperexpansive operators: the unbounded case
The Cauchy dual operator T’, given by , provides a bounded unitary invariant for a closed left-invertible T. Hence, in some special cases, problems in the theory of unbounded Hilbert space operators can be related to similar problems in the theory of bounded Hilbert space operators. In particular, for a closed expansive T with finite-dimensional cokernel, it is shown that T admits the Cowen-Douglas decomposition if and only if T’ admits the Wold-type decomposition (see Definitions 1.1 and 1.2 below)....
On the Banach-Stone problem
Let X and Y be locally compact Hausdorff spaces, let E and F be Banach spaces, and let T be a linear isometry from C₀(X,E) into C₀(Y,F). We provide three new answers to the Banach-Stone problem: (1) T can always be written as a generalized weighted composition operator if and only if F is strictly convex; (2) if T is onto then T can be written as a weighted composition operator in a weak sense; and (3) if T is onto and F does not contain a copy of then T can be written as a weighted composition...
On the generalized Hardy spaces.
On the norm of certain weighted composition operators on the Hardy space.
On Volterra composition operators from Bergman-type space to Bloch-type space
Let be an analytic self-mapping of and an analytic function on . In this paper we characterize the bounded and compact Volterra composition operators from the Bergman-type space to the Bloch-type space. We also obtain an asymptotical expression of the essential norm of these operators in terms of the symbols and .
On weighted composition operators acting between weighted Bergman spaces of infinite order and weighted Bloch type spaces
Let ϕ: → and ψ: → ℂ be analytic maps. They induce a weighted composition operator acting between weighted Bergman spaces of infinite order and weighted Bloch type spaces. Under some assumptions on the weights we give a characterization for such an operator to be bounded in terms of the weights involved as well as the functions ψ and ϕ
Operators on Lorentz sequence spaces
Description of multiplication operators generated by a sequence and composition operators induced by a partition on Lorentz sequence spaces , , is presented.
Order bounded composition operators on the Hardy spaces and the Nevanlinna class
We study the order boundedness of composition operators induced by holomorphic self-maps of the open unit disc D. We consider these operators first on the Hardy spaces 0 < p < ∞ and then on the Nevanlinna class N. Given a non-negative increasing function h on [0,∞[, a composition operator is said to be X,Lh-order bounded (we write (X,Lh)-ob) with or X = N if its composition with the map f ↦ f*, where f* denotes the radial limit of f, is order bounded from X into . We give a complete characterization...