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Related papers: The Schwarz-Pick lemma for slice regular functions

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In this note we consider some generalizations of the Schwarz lemma for harmonic functions on the unit disk, whereby values of such functions and the norms of their differentials at the point $z=0$ are given.

Complex Variables · Mathematics 2019-11-12 Marek Svetlik

We obtain upper bounds for the norm of the Schwarzian derivative of convex holomorphic mappings defined on the polydisk and the unit ball in $\mathbb{C}^n$. For coordinate-wise convex mappings on the polydisk, we derive a sharp estimate…

Complex Variables · Mathematics 2026-04-15 Rodrigo Hernández

We provide generalisations of two Schwarz-type lemmas -- the first a result of Globevnik and the other due to Ransford and White -- for holomorphic mappings into the spectral unit ball. The first concerns mappings of the unit disc in C into…

Complex Variables · Mathematics 2007-05-23 Gautam Bharali

The goal of this paper is to introduce and study some geometric properties of slice regular functions of quaternion variable like univalence, subordination, starlikeness, convexity and spirallikeness in the unit ball. We prove a number of…

Complex Variables · Mathematics 2014-10-13 Sorin G. Gal , J. Oscar González-Cervantes , Irene Sabadini

In this paper we prove a new version of Krein-Langer factorization theorem in the slice hyperholomorphic setting which is more general than the one proved in [D. Alpay, F. Colombo, I. Sabadini, Krein-Langer factorization and related topics…

Complex Variables · Mathematics 2014-06-27 Daniel Alpay , Fabrizio Colombo , Irene Sabadini

We establish the Schwarz Reflection Principle for $J$-complex discs attached to a real analytic $J$-totally real submanifold of an almost complex manifold with real analytic $J$. We also prove the precise boundary regularity and derive the…

Complex Variables · Mathematics 2009-06-29 S. Ivashkovich , A. Sukhov

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 paper we show that the real differential of any injective slice regular function is everywhere invertible. The result is a generalization of a theorem proved by G. Gentili, S. Salamon and C. Stoppato, and it is obtained thanks, in…

Complex Variables · Mathematics 2019-01-03 Amedeo Altavilla

In this paper we prove a Schwarz lemma for the pentablock. The set \[ \mathcal{P}=\{(a_{21}, \text{tr} \ A, \det A) : A=[a_{ij}]_{i,j=1}^2 \in \mathbb{B}^{2\times 2}\} \] where $\mathbb{B}^{2\times 2}$ denotes the open unit ball in the…

Complex Variables · Mathematics 2022-11-29 Nujood M. Alshehri , Zinaida A. Lykova

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

The Schwarz lemmas are well-known characterizations for holomorphic maps and we exhibit two examples of their applications. For a sequence family of biholomorphisms $f_j$, it is useful to determine the location of $f_j(q)$ for a fixed point…

Complex Variables · Mathematics 2015-01-15 Bingyuan Liu

In this paper we continue the study of Bergman theory for the class of slice regular functions. In the slice regular setting there are two possibilities to introduce the Bergman spaces, that are called of the first and of the second kind.…

Complex Variables · Mathematics 2014-06-23 Fabrizio Colombo , J. Oscar Gonzalez-Cervantes , Irene Sabadini

Octonionic analysis is becoming eminent due to the role of octonions in the theory of G2 manifold. In this article, a new slice theory is introduced as a generalization of the holomorphic theory of several complex variables to the…

Complex Variables · Mathematics 2018-12-12 Guangbin Ren , Ting Yang

We prove a version of the Schwarz lemma for holomorphic mappings from the unit disk into the symmetric product of a Riemann surface. Our proof is function-theoretic and self-contained. The main novelty in our proof is the use of the…

Complex Variables · Mathematics 2019-09-10 Jaikrishnan Janardhanan

We prove a Schwarz-type lemma for noncompact manifolds with possibly noncompact boundary. The result is a consequence of a suitable form of the weak maximum principle of independent interest. The paper is enriched with applications to…

Differential Geometry · Mathematics 2016-02-11 Guglielmo Albanese , Marco Rigoli

In this paper, we establish some Schwarz type lemmas for mappings $\Phi$ satisfying the inhomogeneous biharmonic Dirichlet problem $ \Delta (\Delta(\Phi)) = g$ in $\mathbb{D}$, $\Phi=f$ on $\mathbb{T}$ and $\partial_n \Phi=h$ on…

Complex Variables · Mathematics 2020-03-26 Adel Khalfallah , Fathi Haggui , Mohamed Mhamdi

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

Let the function $\varphi$ be holomorphic in the unit disk $\mathbb{D}$ of the complex plane $\mathbb{C}$ and let $\varphi (\mathbb{D})\subset \mathbb{D}$. We study the level sets and the critical points of the hyperbolic derivative of…

Complex Variables · Mathematics 2019-12-09 Juan Arango , Hugo Arbeláez , Diego Mejía

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

For analytic functions in the unit disk, general bounds on the Schwarzian derivative in terms of Nehari functions are shown to imply uniform local univalence and in some cases finite and bounded valence. Similar results are obtained for the…

Complex Variables · Mathematics 2019-05-01 M. Chuaqui , P. Duren , B. Osgood