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Related papers: On Koebe-type functions for harmonic quasiconforma…

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We first construct the harmonic K-quasiconformal Koebe functions, filling a long-standing foundational gap in geometric function theory. This construction provides a unified parametric candidate extremal function framework for conformal…

Complex Variables · Mathematics 2026-03-31 Zhi-Gang Wang , Xiao-Yuan Wang , Antti Rasila , Jia-Le Qiu

In this paper, we first prove the coefficient conjecture of Clunie and Sheil-Small for a class of univalent harmonic functions which includes functions convex in some direction. Next, we prove growth and covering theorems and some related…

Complex Variables · Mathematics 2014-03-25 S. Ponnusamy , A. Sairam Kaliraj

In the present paper, we discuss several basic properties of a class of quasiconformal close-to-convex harmonic mappings with starlike analytic part, such results as coefficient inequalities, an integral representation, a growth theorem, an…

Complex Variables · Mathematics 2021-10-25 Zhi-Gang Wang , Xin-Zhong Huang , Zhi-Hong Liu , Rahim Kargar

We prove that the composition of a quasi-nearly subharmonic function and a quasiregular mappings of bounded multiplicity is quasi-nearly subharmonic. Also, we prove that if $u\circ f$ is quasi-nearly subharmonic for all quasi-nearly…

Functional Analysis · Mathematics 2011-03-09 Pekka Koskela , Vesna Manojlović

Let $\mathcal{H}$ denote the class of harmonic functions $f$ in $\mathbb{D}:= \{z\in \mathbb{C}:|z| < 1\}$ normalized by $f(0) = 0 = f_z(0) -1$. For $\alpha \geq 0$, we consider the following class $$\mathcal{W}^0_{\mathcal{H}}(\alpha):=…

Complex Variables · Mathematics 2016-06-28 Nirupam Ghosh , A. Vasudevarao

In this article, we construct generalized harmonic univalent mappings and find its coefficients bounds. We present the counterexample to validate the coefficient conjecture proposed by Clunie and Sheil-Small for the class of functions…

Complex Variables · Mathematics 2026-02-17 Omendra Mishra , Asena Çetinkaya

We begin by recalling the definition of nonnegative quasinearly subharmonic functions on locally uniformly homogeneous spaces. Recall that these spaces and this function class are rather general: among others subharmonic, quasisubharmonic…

Analysis of PDEs · Mathematics 2011-01-28 Juhani Riihentaus

In 1984, a simple and useful univalence criterion for harmonic functions was given by Clunie and Sheil-Small, which is usually called the shear construction. However, the application of this theorem is limited to the planar harmonic…

Complex Variables · Mathematics 2014-09-29 Małgorzata Michalska , Andrzej Michalski

In this paper, we prove several sharp Bohr-type and Bohr-Rogosinski-type inequalities for $K$-quasiconformal, sense-preserving harmonic mappings on $\mathbb{D}$, whose analytic part is subordinate to a function belonging to the class of…

Complex Variables · Mathematics 2025-08-04 Molla Basir Ahamed , Taimur Rahman

There are many families of functions on partitions, such as the shifted symmetric functions, for which the corresponding q-brackets are quasimodular forms. We extend these families so that the corresponding q-brackets are quasimodular for a…

Number Theory · Mathematics 2022-12-16 Jan-Willem M. van Ittersum

Generalizing older works of Domar and Armitage and Gardiner, we give an inequality for quasinearly subharmonic functions. As an application of this inequality, we improve Domar's, Rippon's and our previous results concerning the existence…

Analysis of PDEs · Mathematics 2017-01-17 Juhani Riihentaus

This paper focuses on estimating the Taylor coefficients for Hilbert spaces of holomorphic functions on the disk using intrinsic features of univalent functions and of Teichmuller spaces. Estimating these coefficients has a long history but…

Complex Variables · Mathematics 2026-05-20 Samuel L Krushkal

We study conjugate-type phenomena for complex-valued harmonic quasiregular mappings in the unit disk across three function space families: $Q(n,p,\alpha)$, $F(p,q,s)$, and the non-derivative $M(p,q,s)$. For a harmonic $K$-quasiregular…

Complex Variables · Mathematics 2026-01-13 Jihua Sun , Junming Liu , Zhi-Gang Wang

The purpose of this paper is twofold. First, we establish several sharp Hardy-Littlewood type radial growth theorems for harmonic $(K,K')$-quasiregular mappings. Second, we prove some sharp coefficient growth theorems for such mappings. In…

Complex Variables · Mathematics 2025-09-23 Shaolin Chen

In this article, we study Bohr-type inequalities involving a parameter or convex combinations for $K$-quasiconformal, sense-preserving harmonic mappings in $\mathbb{D}$, where the analytic part is subordinate to a convex function. Moreover,…

Complex Variables · Mathematics 2025-09-11 Molla Basir Ahamed , Taimur Rahman

Let $\mathcal{S}_H^0(K)$, $K\ge 1$, be the class of normalized $K$-quasiconformal harmonic mappings in the unit disk. We obtain Baernstein type extremal results for the analytic and co-analytic parts of functions in the geometric subclasses…

Complex Variables · Mathematics 2025-10-21 Suman Das , Jie Huang , Antti Rasila

We introduce dual Hopf algebras which simultaneously combine the concepts of the k-Schur function theory with the quasi-symmetric Schur function theory. We construct dual basis of these Hopf algebras with remarkable properties.

Combinatorics · Mathematics 2012-05-11 Chris Berg , Luis Serrano

The Schur functions, a basis for the symmetric polynomials (Sym), encode the irreducible representations of the symmetric group, $\mathfrak{S}_n$, via the Frobenius characteristic map. In 1996, Krob and Thibon defined a quasisymmetric…

Combinatorics · Mathematics 2024-05-20 Angela Hicks , Samantha Miller-Brown

This article serves as an introduction to several recent developments in the study of quasisymmetric functions. The focus of this survey is on connections between quasisymmetric functions and the combinatorial Hopf algebra of noncommutative…

Combinatorics · Mathematics 2018-10-17 Sarah K. Mason

On a complete Calabi-Yau manifold $M$ with maximal volume growth, a harmonic function with subquadratic polynomial growth is the real part of a holomorphic function. This generalizes a result of Conlon-Hein. We prove this result by proving…

Differential Geometry · Mathematics 2024-10-24 Shih-Kai Chiu
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