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Related papers: A reverse Schwarz--Pick inequality

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This paper establishes a sharp Schwarz-Pick type inequality for real-valued invariant harmonic functions defined on the complex unit ball $\mathbb B^n$. The proof of this main result simultaneously provides a solution to a natural extension…

Complex Variables · Mathematics 2026-02-13 Kapil Jaglan , Aeryeong Seo

We prove a ``general shrinking lemma'' that resembles the Schwarz--Pick--Ahlfors Lemma and its many generalizations, but differs in applying to maps of a finite disk into a disk, rather than requiring the domain of the map to be complete.…

Complex Variables · Mathematics 2016-09-07 Robert Osserman

In this note we establish a Schwarz type inequality for holomorphic mappings between unit balls $B_n$ and $B_m$ in corresponding complex spaces.

Complex Variables · Mathematics 2015-04-28 David Kalaj

Two different problems are considered here. First, a characterization of sampling sequences for the class of analytic functions from the disc into itself is given. Second, a version of Schwarz-Pick Lemma for $n$ points leads to an…

Complex Variables · Mathematics 2023-08-03 Nacho Monreal Galan , Michael Papadimitrakis

The Schwarz lemma as one of the most influential results in complex analysis and it has a great impact to the development of several research fields, such as geometric function theory, hyperbolic geometry, complex dynamical systems, and…

Complex Variables · Mathematics 2017-04-25 Miodrag Mateljević

We prove a Schwarz-Jack lemma for holomorphic functions on the unit disk with the property that their maximum modulus on each circle about the origin is attained at a point on the positive real axis. With the help of this result, we…

Complex Variables · Mathematics 2026-04-10 Javad Mashreghi , Annika Moucha , Ryan O'Loughlin , Thomas Ransford , Oliver Roth

We establish some estimates of the the angular derivatives from below for holomorphic self-maps of the unit disk at one and two fixed points of the unit circle provided there is no fixed point inside the unit disk. The results complement…

Complex Variables · Mathematics 2013-09-13 A. Frolova , M. Levenshtein , D. Shoikhet , A. Vasil'ev

We study the Schwarz lemma for harmonic functions and prove sharp versions for the cases of real harmonic functions and the norm of harmonic mappings.

Complex Variables · Mathematics 2012-02-21 David Kalaj , Matti Vuorinen

It is well-known that the classical Schwarz lemma yields an explicit comparison of two Hermitian metrics with uniform constant negative curvature bounds through holomorphic maps between complex manifolds. In this paper, we establish Schwarz…

Differential Geometry · Mathematics 2024-12-05 Zhiyao Xiong , Xiaokui Yang , Shing-Tung Yau

The aim of this paper is twofold. First, we obtain a Schwarz-Pick type lemma for the $\alpha$-harmonic mapping $u=P_{\alpha}[\phi]$, where $\phi\in L^{p}(\mathbb{S}^{n-1},\mathbb{R} )$ and $p\in[1,\infty]$. We get an explicit form of the…

Analysis of PDEs · Mathematics 2025-09-09 Vibhuti Arora , Jiaolong Chen , Shankey Kumar , Qianyun Li

We prove a sharp Schwarz-type lemma for meromorphic functions with spherical derivative uniformly bounded away from zero. As a consequence we deduce an improved quantitative version of a recent normality criterion due to Grahl & Nevo and…

Complex Variables · Mathematics 2020-03-04 Richard Fournier , Daniela Kraus , Oliver Roth

We consider the multi-point Schwarz-Pick lemma and its associate functions due to Beardon-Minda and Baribeau-Rivard-Wegert. Basic properties of the associate functions are summarized. Then we observe that special cases of the multi-point…

Complex Variables · Mathematics 2011-02-03 Kyung Hyun Cho , Seong-A Kim , Toshiyuki Sugawa

Suppose $w$ is a sense-preserving harmonic mapping of the unit disk $\mathbb{D}$ such that $w(\mathbb{D})\subseteq\mathbb{D}$ and $w$ has a zero of order $p\geq1$ at $z=0$. In this paper, we first improve the Schwarz lemma for $w$, and…

Complex Variables · Mathematics 2020-07-28 Xiao-Jin Bai , Jie Huang , Jian-Feng Zhu

There is a known generalization of the classical Schwarz lemma to holomorphic functions from the polydisk to the disk. In this paper, we characterize those functions which satisfy equality everywhere in this generalized inequality: they are…

Complex Variables · Mathematics 2013-02-06 Greg E. Knese

The aim of this paper is to establish some properties of solutions to the Dirichlet-Neumann problem: $(\partial_z\partial_{\overline{z}})^2 w=g$ in the unit disc $\ID$, $w=\gamma_0$ and…

Complex Variables · Mathematics 2021-03-17 Peijin Li , Qinghong Luo , Saminathan Ponnusamy

In this paper, we present an alternative and elementary proof of a sharp version of the classical boundary Schwarz lemma by Frolova et al. with initial proof via analytic semigroup approach and Julia-Carath\'eodory theorem for univalent…

Complex Variables · Mathematics 2015-02-10 Guangbin Ren , Xieping Wang

A sharp version of a recent inequality of Kovalev and Yang on the ratio of the $(H^1)^\ast$ and $H^4$ norms for certain polynomials is obtained. The inequality is applied to establish a sharp and tractable sufficient condition for the…

Complex Variables · Mathematics 2021-01-12 Ole Fredrik Brevig , Joaquim Ortega-Cerdà , Kristian Seip

In this paper, we prove a general Schwarz lemma at the boundary for holomorphic mappings from the polydisc to the unit ball in any dimensions. For the special case of one complex variable, the obtained results give the classic boundary…

Complex Variables · Mathematics 2014-11-04 Yang Liu , Zhihua Chen , Yifei Pan

In this note, we prove a Schwarz-Pick type lemma for minimal maps between negatively curved Riemannian surfaces. More precisely, we prove that if $f:M \to N$ is a minimal map with bounded Jacobian between two complete negatively curved…

Differential Geometry · Mathematics 2019-04-02 Andreas Savas-Halilaj

We obtain a generalization of the Burns-Krantz rigidity theorem for holomorphic self-mappings of the unit disk in the spirit of the classical Schwarz-Pick Lemma and its continuous version due to L.Harris via the generation theory for…

Complex Variables · Mathematics 2007-05-23 David Shoikhet