English
Related papers

Related papers: Uniqueness theorems for Korenblum type spaces

200 papers

We study radial behavior of analytic and harmonic functions, which admit a certain majorant in the unit disk. We prove that extremal growth or decay may occur only along small sets of radii and give precise estimates of these exceptional…

Classical Analysis and ODEs · Mathematics 2012-09-20 A. Borichev , Yu. Lyubarskii , E. Malinnikova , P. Thomas

Let $u\not\equiv -\infty$ be a subharmonic function on the complex plane $\mathbb C$. In 2016, we obtained a result on the existence of an entire function $f\neq 0$ satisfying the estimate $\log|f|\leq {\sf B}_u$ on $\mathbb C$, where…

Complex Variables · Mathematics 2020-04-27 Bulat N. Khabibullin

In this very short paper, we provide a strong motivation for the study of the following problem: given a real normed space $E$, a closed, convex, unbounded set $X\subseteq E$ and a function $f:X\to X$, find suitable conditions under which,…

Functional Analysis · Mathematics 2020-07-23 Biagio Ricceri

We investigate certain classes of shift invariant subspaces in growth spaces on the unit disc of the complex plane determined by a majorant $w$, which include the classical Korenblum growth spaces. Our main result provides a complete…

Complex Variables · Mathematics 2023-08-08 Adem Limani

We obtain extremal majorants and minorants of exponential type for a class of even functions on $\R$ which includes $\log |x|$ and $|x|^\alpha$, where $-1 < \alpha < 1$. We also give periodic versions of these results in which the majorants…

Classical Analysis and ODEs · Mathematics 2011-06-06 Emanuel Carneiro , Jeffrey D. Vaaler

We present an approximation theorem for continuous non-decreasing functions on compact preordered spaces, leading to an algebraic characterization of their corresponding function spaces. As an application, we prove that the family of…

Functional Analysis · Mathematics 2025-12-04 Ettore Minguzzi

Let $X$ be a locally compact topological space, $(Y,d)$ be a boundedly compact metric space and $LB(X,Y)$ be the space of all locally bounded functions from $X$ to $Y$. We characterize compact sets in $LB(X,Y)$ equipped with the topology of…

General Topology · Mathematics 2018-03-29 Ľubica Holá , Dušan Holý

Let $E$ be an arbitrary subset of the unit circle $T$ and let $f$ be a function defined on $E$. When there exist polynomials $P_n$ which are uniformly bounded by a number $M > 0$ on $T$ and converge (pointwise) to $f$ at each point of $E$?…

Complex Variables · Mathematics 2015-01-05 Arthur A. Danielyan

We study the vanishing cycle complex $\varphi_fA_X$ for a holomorphic function $f$ on a reduced complex analytic space $X$ with $A$ a Dedekind domain (for instance, a localization of the ring of integers of a cyclotomic field, where the…

Algebraic Geometry · Mathematics 2020-09-25 Morihiko Saito

Let $\mathcal{S}$ denote the family of all functions that are analytic and univalent in the unit disk $\mathbb{D}:=\{z: |z|<1\}$ and satisfy $f(0)=f^{\prime}(0)-1=0$. In the present paper, we consider certain subclasses of univalent…

Complex Variables · Mathematics 2020-03-24 Lei Shi , Zhi-Gang Wang , Ren-Li Su , Muhammad Arif

In this paper, we introduce a class of function spaces called K\"othe-Herz spaces $E(\mathcal{X})$. These spaces are similar to amalgam spaces and are characterized by a local component given by a countable family $\mathcal{X}=\left(…

Functional Analysis · Mathematics 2023-05-16 M. Ashraf Bhat , P. Kolwicz , G. Sankara Raju Kosuru

In this short note we prove an optimal version of a classical result. Given a majorant determining a growth restriction on functions in the unit disk $\mathbb{D}$, we say that a set $E$ on the unit circle $\mathbb{T}$ is a uniqueness set,…

Complex Variables · Mathematics 2025-06-10 Bartosz Malman

It is known that, if $S(z)$ is a non-constant, singular inner function defined on the unit disk, then $\min_{|z|\le r}|S(z)|\to0$ as $r\to1^-$. We show that the convergence may be arbitrarily slow.

Complex Variables · Mathematics 2023-06-22 Thomas Ransford

Consider a semi-algebraic function $f\colon\mathbb{R}^n \to {\mathbb{R}},$ which is continuous around a point $\bar{x} \in \mathbb{R}^n.$ Using the so--called {\em tangency variety} of $f$ at $\bar{x},$ we first provide necessary and…

Optimization and Control · Mathematics 2020-02-24 Tien-Son Pham

For a transcendental entire function $f$, the property that there exists $r>0$ such that $m^n(r)\to\infty$ as $n\to\infty$, where $m(r)=\min \{|f(z)|:|z|=r\}$, is related to conjectures of Eremenko and of Baker, for both of which order…

Complex Variables · Mathematics 2021-02-04 Daniel A. Nicks , Philip J. Rippon , Gwyneth M. Stallard

The general theme of this note is illustrated by the following theorem: Theorem 1. Suppose $K$ is a compact set in the complex plane and 0 belongs to the boundary $\partial K$. Let ${\cal A}(K)$ denote the space of all functions $f$ on $K$…

Functional Analysis · Mathematics 2016-09-07 N. V. Rao

There have been, over the last 8 years, a number of far reaching extensions of the famous original F. and M. Riesz's uniqueness theorem that states that if a bounded analytic function in the unit disc of the complex plane $\Bbb C$ has the…

Complex Variables · Mathematics 2007-05-23 Enrique Villamor

Let F be a class of functions with the uniqueness property: if a function f in F vanishes on a set of positive measure, then f is the zero function. In many instances, we would like to have a quantitative version of this property, e.g. a…

Classical Analysis and ODEs · Mathematics 2007-05-23 Alexander Borichev , Fedor Nazarov , Mikhail Sodin

For $\alpha > 0$, the $\alpha$-Lipschitz minorant of a function $f: \mathbb{R} \to \mathbb{R}$ is the greatest function $m : \mathbb{R} \to \mathbb{R}$ such that $m \leq f$ and $|m(s)-m(t)| \le \alpha |s-t|$ for all $s,t \in \mathbb{R}$,…

Probability · Mathematics 2012-03-06 Joshua Abramson , Steven N. Evans

We study locally univalent functions $f$ analytic in the unit disc $\mathbb{D}$ of the complex plane such that $|{f"(z)/f'(z)}|(1-|z|^2)\leq 1+C(1-|z|)$ holds for all $z\in\mathbb{D}$, for some $0<C<\infty$. If $C\leq 1$, then $f$ is…

Complex Variables · Mathematics 2017-05-17 Juha-Matti Huusko , Toni Vesikko
‹ Prev 1 2 3 10 Next ›