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Conformal mapping may be the best-known topic in complex analysis. Any simply connected nonempty domain $\Omega$ in the complex plane ${{\mathbb{C}}}$ (assuming $\Omega\ne {{\mathbb{C}}}$) can be mapped bijectively to the unit disk by an…

Complex Variables · Mathematics 2025-07-22 Lloyd N. Trefethen

Extremal length is a classical tool in 1-dimensional complex analysis for building conformal invariants. We propose a higher-dimensional generalization for complex manifolds and provide some ideas on how to estimate and calculate it. We…

Complex Variables · Mathematics 2020-06-26 Tommaso Pacini

Let $X$ be a compact Riemann surface of genus $\geq 2$ of constant negative curvature -1. An extremal disk is an embedded (resp. covering) disk of maximal (resp. minimal) radius. A surface containing an extremal disk is an {\em extremal…

Differential Geometry · Mathematics 2007-05-23 Alina Vdovina

We define a new type of Hardy-Orlicz spaces of conformal mappings on the unit disk where in place of the value |f(x)| we consider the intrinsic path distance between f(x) and f(0) in the image domain. We show that if the Orlicz function is…

Complex Variables · Mathematics 2015-06-12 Pekka Koskela , Sita Benedict

We discuss approximation of extremal functions by polynomials in the weighted Bergman spaces $A^p_\alpha$ where $-1 < \alpha < 0$ and $-1 < \alpha < p-2$. We obtain bounds on how close the approximation is to the true extremal function in…

Complex Variables · Mathematics 2017-05-19 Timothy Ferguson

This note examines sufficient conditions for the quasiconformal extendibility of harmonic mappings defined in the unit disk. It is demonstrated that a harmonic strongly starlike mapping admits a quasiconformal extension to the entire plane,…

Complex Variables · Mathematics 2025-09-03 Xiu-Shuang Ma

Let ${H^p}\left( \mathbb{D} \right)$ be the Hardy space of all holomorphic functions on the unit disk $\mathbb{D}$ with exponent $p>0$. If $D\ne \mathbb{C}$ is a simply connected domain and $f$ is the Riemann mapping from $\mathbb{D}$ onto…

Complex Variables · Mathematics 2022-01-31 Christina Karafyllia

We consider quasiconformal mappings of the unit disk that have a planar extension which have $p$-integrable distortion. In this paper, we establish a bound for the modulus of continuity for the inverse mapping and show sharpness of this…

Complex Variables · Mathematics 2022-08-05 Olli Hirviniemi , Lauri Hitruhin

We study conformal mappings from the unit disk (or a rectangle) to one-tooth gear-shaped planar domains from the point of view of the Schwarzian derivative, with emphasis on numerical considerations. Applications are given to evaluation of…

Complex Variables · Mathematics 2024-10-15 Philip R. Brown , R. Michael Porter

We find an extremal problem for conformal maps on a finitely connected subregion of the Riemann sphere containing the point at infinity whose unique solution is a map onto a square domain, that is, a domain whose complementary components…

Complex Variables · Mathematics 2016-06-02 Mario Bonk

We provide some new estimates for distances in harmonic function spaces of several variables related to mixed norm spaces.Some of them extend previously known assertions in this direction in the unit ball and upperhalfspace.

Complex Variables · Mathematics 2014-01-06 Romi F. Shamoyan

In this paper, we investigate some properties of planar harmonic mappings. First, we generalize the main results in \cite{CPW3} and \cite{HT}, and then discuss the relationship between area integral means and harmonic Hardy spaces or…

Complex Variables · Mathematics 2012-03-14 SH. Chen , S. Ponnusamy , X. Wang

Let $\mathbb D$ be the unit disc in $\mathbb C$ and let $f:\mathbb D \to \mathbb C$ be a Riemann map, $\Delta=f(\mathbb D)$. We give a necessary and sufficient condition in terms of hyperbolic distance and horocycles which assures that a…

Complex Variables · Mathematics 2018-06-19 Filippo Bracci , Manuel D. Contreras , Santiago Díaz-Madrigal , Hervé Gaussier

We introduce the notion of extremal basis of tangent vector fields at a boundary point of finite type of a pseudo-convex domain in $\mathbb{C}^n$. Then we define the class of geometrically separated domains at a boundary point, and give a…

Complex Variables · Mathematics 2014-07-10 Philippe Charpentier , Yves Dupain

We prove a general criterion for a metric space to have conformal dimension one. The conditions are stated in terms of the existence of enough local cut points in the space. We then apply this criterion to the boundaries of hyperbolic…

Metric Geometry · Mathematics 2013-11-05 Matias Carrasco Piaggio

We show how to express a conformal map of a general two connected domain in the plane such that neither boundary component is a point to a representative domain which has the virtue of having an explicit algebraic Bergman kernel function.…

Complex Variables · Mathematics 2008-01-16 Steven R. Bell , Ersin Deger , Thomas Tegtmeyer

The Riemann Theorem states, that for any nontrivial connected and simply connected domain on the Riemann sphere there exists some its conformal bijection to the exterior of the unit disk. In this paper we find an explicit form of this map…

Complex Variables · Mathematics 2007-05-23 S. M. Natanzon

We consider random i.i.d. samples of absolutely continuous measures on bounded connected domains. We prove an upper bound on the $\infty$-transportation distance between the measure and the empirical measure of the sample. The bound is…

Probability · Mathematics 2014-07-07 Nicolás García Trillos , Dejan Slepčev

We give solutions to some extremal problems involving distance function in mixed norm spaces of harmonic functions on the unit ball of R^n

Complex Variables · Mathematics 2012-01-18 Milos Arsenovic , Romi Shamoyan

We investigate extremal metrics at which various types of rigidity theorems involving scalar curvatures hold. The rigidity we discuss here is related to the rigidity theorems presented by Mario Listing in his previous preprint. More…

Differential Geometry · Mathematics 2026-04-08 Shota Hamanaka