An analytic representation for selfmaps of a countably infinite set and its cycles. (Short Communication).
An analytic representation for selfmaps of a countably infinite set and its cycles.
An integral extrapolation theorem with applcations
An IntroduCtion into the Theory of Sequence Spaces and Measures of Noncompactness
An operator characterization of -spaces in a class of Orlicz spaces
We consider an embedding of the group of invertible transformations of [0,1] into the algebra of bounded linear operators on an Orlicz space. We show that if this embedding preserves the group action then the Orlicz space is an -space for some 1 ≤ p < ∞.
An operator-theoretic approach to truncated moment problems
We survey recent developments in operator theory and moment problems, beginning with the study of quadratic hyponormality for unilateral weighted shifts, its connections with truncated Hamburger, Stieltjes, Hausdorff and Toeplitz moment problems, and the subsequent proof that polynomially hyponormal operators need not be subnormal. We present a general elementary approach to truncated moment problems in one or several real or complex variables, based on matrix positivity and extension. Together...
An overview of some recent developments on the Invariant Subspace Problem
This paper presents an account of some recent approaches to the Invariant Subspace Problem. It contains a brief historical account of the problem, and some more detailed discussions of specific topics, namely, universal operators, the Bishop operators, and Read’s Banach space counter-example involving a finitely strictly singular operator.
Application of sequential shifts to an interpolation problem.
In the present paper initial operators for a right invertible operator, which are induced by sequential shifts and have the property c(R) are constructed. An application to the Lagrange type interpolation problem is given. Moreover, an example with the Pommiez operator is studied.
Asymptotically cyclic quasianalytic contractions
The study of quasianalytic contractions, motivated by the hyperinvariant subspace problem, is continued. Special emphasis is put on the case when the contraction is asymptotically cyclic. New properties of the functional commutant are explored. Analytic contractions and bilateral weighted shifts are discussed as illuminating examples.
Asymptotically holomorphic functions and translation invariant subspaces of weighted Hilbert spaces of sequences