Construction of analytic functions, which determine bounded Toeplitz operators
Construction of analytic functions, which determine bounded Toeplitz operators
arXiv subjects
Publications and source records attributed to Peyo Stoilov.
Construction of analytic functions, which determine bounded Toeplitz operators
Let ${\rm {\mathbb G}}$ be a domain with closed rectifiable Jordan curve $\ell $ . Let $K({\rm {\mathbb G}})$ be the space of all analytic functions in ${\rm {\mathbb G}} $ representable by a Cauchy - Stieltjes integral. Let ${\rm {\mathfrak M}}(K)$ be the class of all multipliers of the space $K({\rm {\mathbb G}}).$ In this paper we prove that if $f$ is bounded analytic function on ${\rm {\mathbb G}}$ and $${\kern 1pt} {\kern 1pt} {\kern 1pt} \mathop{ess\sup}\limits_{η\in \ell } \int_{\ell} \frac{|f(ζ)-f(η)|}{|ζ-η|} |dζ|{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} <\infty {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} ,$$ then $f\in {\rm {\mathfrak M}}(K)$ . If ${\rm {\mathbb G}}={\rm {\mathbb D}}$ is the unit disc, this theorem was proved for the first time by V. P. Havin. In particular for a smooth curve $\ell $ we prove that if $f'\in E^{p} ({\rm {\mathbb G}}),{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} p>1,$ then $f\in {\rm {\mathfrak M}}(K),$ where $E^{p} ({\rm {\mathbb G}})$ are the spaces of Smirnov.
It is proved an inequality - integrated analogue of the Hardy inequality and as application simplified proof of the theorem of S. A. Vinogradov for the bounded Toeplitz operators on the space of functions analytic and bounded in the unit disc is given.
In this paper we prove some interpolation theorems for the multipliers of the Cauchy- Stiltjes type integrals
BMO estimates and the radial growth of Bloch functions have been studied by B. Korenblum [3]. The present paper contains some natural generalizations of these results.
Special classes of analytic functions, denoting by K and J arc considered in this paper.
The present note contains a generalization of a theorem of Hallenbeck and Samotij for the multipliers of Cauchy integrals of logarithmic potentials.
An elementary method is given for estimates of the norms of the Toeplitz operators, determined by rational inner functions
A new proof of the inequalities of D. J. Hallenbeck for the Area functions of multipliers of fractional Cauchy transforms is given.
The present paper contains a generalization of some interpolation theorems of S. A. Vinogradov.
In this note is given a new proof of the norm estimate of J. Cima and A. Matheson.