Random Dirichlet Functions: Multipliers and Smoothness

1993 ◽  
Vol 45 (2) ◽  
pp. 255-268 ◽  
Author(s):  
W. George Cochran ◽  
Joel H. Shapiro ◽  
David C. Ullrich
Keyword(s):  
Power Series ◽  
Holomorphic Function ◽  
Dirichlet Series ◽  
Dirichlet Space ◽  
General Setting ◽  
Sufficient Condition ◽  
Dirichlet Spaces ◽  
Random Series ◽  
Weighted Dirichlet Spaces ◽  
Almost All

AbstractWe show that if is a holomorphic function in the Dirichlet space of the unit disk, then almost all of its randomizations are multipliers of that space. This parallels a known result for lacunary power series, which also has a version for smoothness classes: every lacunary Dirichlet series lies in the Lipschitz class Lip1/2 of functions obeying a Lipschitz condition with exponent 1/2. However, unlike the lacunary situation, no corresponding “almost sure” Lipschitz result is possible for random series: we exhibit a Dirichlet function with norandomization in Lip1/2. We complement this result with a “best possible” sufficient condition for randomizations to belong almost surely to Lip1/2. Versions of our results hold for weighted Dirichlet spaces, and much of our work is carried out in this more general setting.

scholarly journals Cyclicity in Dirichlet Spaces

2019 ◽  
Vol 62 (02) ◽  
pp. 247-257 ◽  
Author(s):  
Y. Elmadani ◽  
I. Labghail
Keyword(s):  
Continuous Function ◽  
Unit Circle ◽  
Borel Measure ◽  
Dirichlet Space ◽  
Sufficient Condition ◽  
Dirichlet Spaces ◽  
Closed Unit Disk ◽  
Finite Borel Measure ◽  
Weighted Dirichlet Space ◽  
Uniformly Continuous

AbstractLet $\unicode[STIX]{x1D707}$ be a positive finite Borel measure on the unit circle and ${\mathcal{D}}(\unicode[STIX]{x1D707})$ the associated harmonically weighted Dirichlet space. In this paper we show that for each closed subset $E$ of the unit circle with zero $c_{\unicode[STIX]{x1D707}}$ -capacity, there exists a function $f\in {\mathcal{D}}(\unicode[STIX]{x1D707})$ such that $f$ is cyclic (i.e., $\{pf:p\text{ is a polynomial}\}$ is dense in ${\mathcal{D}}(\unicode[STIX]{x1D707})$ ), $f$ vanishes on $E$ , and $f$ is uniformly continuous. Next, we provide a sufficient condition for a continuous function on the closed unit disk to be cyclic in ${\mathcal{D}}(\unicode[STIX]{x1D707})$ .

Compact differences of composition operators on weighted Dirichlet spaces

2014 ◽  
Vol 12 (7) ◽  
Author(s):  
Robert Allen ◽  
Katherine Heller ◽  
Matthew Pons
Keyword(s):  
Analytic Functions ◽  
Composition Operators ◽  
Dirichlet Space ◽  
Complex Interpolation ◽  
Dirichlet Spaces ◽  
Space Of Analytic Functions ◽  
First Derivative ◽  
Weighted Dirichlet Spaces ◽  
The Difference

AbstractHere we consider when the difference of two composition operators is compact on the weighted Dirichlet spaces . Specifically we study differences of composition operators on the Dirichlet space and S 2, the space of analytic functions whose first derivative is in H 2, and then use Calderón’s complex interpolation to extend the results to the general weighted Dirichlet spaces. As a corollary we consider composition operators induced by linear fractional self-maps of the disk.

THE ESSENTIAL NORMS OF COMPOSITION OPERATORS ON WEIGHTED DIRICHLET SPACES

2018 ◽  
Vol 97 (2) ◽  
pp. 297-307
Author(s):  
YUFEI LI ◽  
YUFENG LU ◽  
TAO YU
Keyword(s):  
Composition Operator ◽  
Unit Disc ◽  
Composition Operators ◽  
Dirichlet Space ◽  
Essential Norm ◽  
Angular Derivative ◽  
Dirichlet Spaces ◽  
Closed Unit Disc ◽  
Weighted Dirichlet Spaces

Let $\unicode[STIX]{x1D711}$ be an analytic self-map of the unit disc. If $\unicode[STIX]{x1D711}$ is analytic in a neighbourhood of the closed unit disc, we give a precise formula for the essential norm of the composition operator $C_{\unicode[STIX]{x1D711}}$ on the weighted Dirichlet spaces ${\mathcal{D}}_{\unicode[STIX]{x1D6FC}}$ for $\unicode[STIX]{x1D6FC}>0$. We also show that, for a univalent analytic self-map $\unicode[STIX]{x1D711}$ of $\mathbb{D}$, if $\unicode[STIX]{x1D711}$ has an angular derivative at some point of $\unicode[STIX]{x2202}\mathbb{D}$, then the essential norm of $C_{\unicode[STIX]{x1D711}}$ on the Dirichlet space is equal to one.

Binomial subsampling

2006 ◽  
Vol 462 (2068) ◽  
pp. 1181-1195 ◽  
Author(s):  
Carsten Wiuf ◽  
Michael P.H Stumpf
Keyword(s):  
Mathematical Biology ◽  
Power Series ◽  
Generating Functions ◽  
Binomial Distribution ◽  
Random Variable ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
The Family ◽  
Necessary And Sufficient ◽  
Finite Moments

In this paper, we discuss statistical families with the property that if the distribution of a random variable X is in , then so is the distribution of Z ∼Bi( X ,  p ) for 0≤ p ≤1. (Here we take Z ∼Bi( X ,  p ) to mean that given X = x ,  Z is a draw from the binomial distribution Bi( x ,  p ).) It is said that the family is closed under binomial subsampling. We characterize such families in terms of probability generating functions and for families with finite moments of all orders we give a necessary and sufficient condition for the family to be closed under binomial subsampling. The results are illustrated with power series and other examples, and related to examples from mathematical biology. Finally, some issues concerning inference are discussed.

scholarly journals The power series coefficients of functions defined Dirichlet series

1961 ◽  
Vol 5 (1) ◽  
pp. 43-44 ◽  
Author(s):  
W. E. Briggs ◽  
R. G. Buschman
Keyword(s):  
Power Series ◽  
Dirichlet Series

Basic Properties and Examples of Dirichlet Forms

2011 ◽  
Author(s):  
Zhen-Qing Chen ◽  
Masatoshi Fukushima
Keyword(s):  
Markov Process ◽  
Potential Theory ◽  
Dirichlet Form ◽  
Dirichlet Space ◽  
Dirichlet Forms ◽  
Dirichlet Spaces ◽  
Basic Properties ◽  
Time Changes ◽  
Symmetric Operators ◽  
Analytic Potential

This chapter introduces the concepts of the transience, recurrence, and irreducibility of the semigroup for general Markovian symmetric operators and presents their characterizations by means of the associated Dirichlet form as well as the associated extended Dirichlet space. These notions are invariant under the time changes of the associated Markov process. The chapter then presents some basic examples of Dirichlet forms, with special attention paid to their basic properties as well as explicit expressions of the corresponding extended Dirichlet spaces. Hereafter the chapter discusses the analytic potential theory for regular Dirichlet forms, and presents some conditions for the demonstrated Dirichlet form (E,F) to be local.

Girsanov Transformations for Non-Symmetric Diffusions

2009 ◽  
Vol 61 (3) ◽  
pp. 534-547 ◽  
Author(s):  
Chuan-Zhong Chen ◽  
Wei Sun
Keyword(s):  
Diffusion Process ◽  
Dirichlet Form ◽  
Dirichlet Space ◽  
Explicit Representation ◽  
Dual Process ◽  
Sufficient Condition ◽  
Dual Processes ◽  
Necessary And Sufficient Condition ◽  
Necessary And Sufficient ◽  
Girsanov Transformations

Abstract.Let X be a diffusion process, which is assumed to be associated with a (non-symmetric) strongly local Dirichlet form (ℰ, 𝓓 (ℰ)) on L2(E ;m). For u ∈ 𝓓(ℰ)e, the extended Dirichlet space, we investigate some properties of the Girsanov transformed process Y of X . First, let be the dual process of X and Ŷ the Girsanov transformed process of . We give a necessary and sufficient condition for (Y , Ŷ to be in duality with respect to the measure e2um. We also construct a counterexample, which shows that this condition may not be satisfied and hence (Y , Ŷ ) may not be dual processes. Then we present a sufficient condition under which Y is associated with a semi-Dirichlet form. Moreover, we give an explicit representation of the semi-Dirichlet form.

A Multiplicative Analogue of Schur's Tauberian Theorem

2003 ◽  
Vol 46 (3) ◽  
pp. 473-480 ◽  
Author(s):  
Karen Yeats
Keyword(s):  
Power Series ◽  
Asymptotic Behaviour ◽  
Dirichlet Series ◽  
Tauberian Theorem ◽  
Partial Sums ◽  
Regularly Varying Functions ◽  
Regularly Varying

AbstractA theorem concerning the asymptotic behaviour of partial sums of the coefficients of products of Dirichlet series is proved using properties of regularly varying functions. This theorem is a multiplicative analogue of Schur's Tauberian theorem for power series.

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