English
Related papers

Related papers: Landau's theorem for slice regular functions on th…

200 papers

Slice analysis is a generalization of the theory of holomorphic functions of one complex variable to quaternions. Among the new phenomena which appear in this context, there is the fact that the convergence domain of…

Complex Variables · Mathematics 2021-01-26 Xinyuan Dou , Guangbin Ren , Irene Sabadini

For a slice--regular quaternionic function $f,$ the classical exponential function $\exp f$ is not slice--regular in general. An alternative definition of exponential function, the $*$-exponential $\exp_*$, was given: if $f$ is a…

Complex Variables · Mathematics 2024-03-12 Graziano Gentili , Jasna Prezelj , Fabio Vlacci

The quaternionic valued functions of a quaternionic variable, often referred to as slice regular functions has been studied extensively due to the large number of generali\-zed results of the theory of one complex variable, see…

Complex Variables · Mathematics 2021-11-11 José Oscar González-Cervantes

We study several aspects concerning slice regular functions mapping the quaternionic open unit ball into itself. We characterize these functions in terms of their Taylor coefficients at the origin and identify them as contractive…

Complex Variables · Mathematics 2013-08-13 Daniel Alpay , Vladimir Bolotnikov , Fabrizio Colombo , Irene Sabadini

In this paper we develop a functional calculus for bounded operators defined on quaternionic Banach spaces. This calculus is based on the notion of slice-regularity, see \cite{gs}, and the key tools are a new resolvent operator and a new…

Spectral Theory · Mathematics 2010-03-30 F. Colombo , G. Gentili , I. Sabadini , D. C. Struppa

We prove a version of the classical Mittag-Leffler Theorem for regular functions over quaternions. Our result relies upon an appropriate notion of principal part, that is inspired by the recent definition of spherical analyticity.

Complex Variables · Mathematics 2017-11-15 Graziano Gentili , Giulia Sarfatti

This paper is concerned with a class of generalized slice Fueter-regular functions on arbitrary domains in O with local stem functions. Some classical theorems such as the maximum modulus principle will be generalized to our setting. Some…

Complex Variables · Mathematics 2026-05-12 Xinyuan Dou , Guangbin Ren , Zeping Zhu , Ting Yang

In this paper we prove a quaternionic positive real lemma as well as its generalized version, in case the associated kernel has negative squares for slice hyperholomorphic functions. We consider the case of functions with positive real part…

Complex Variables · Mathematics 2018-10-16 D. Alpay , F. Colombo , I. Lewkowicz , I. Sabadini

In this article we investigate harmonicity, Laplacians, mean value theorems and related topics in the context of quaternionic analysis. We observe that a Mean Value Formula for slice regular functions holds true and it is a consequence of…

Complex Variables · Mathematics 2020-11-09 Cinzia Bisi , Joerg Winkelmann

The recent definition of slice regular function of several quaternionic variables suggests a new notion of quaternionic manifold. We give the definition of quaternionic regular manifold, as a space locally modeled on $\mathbb{H}^n$, in a…

Complex Variables · Mathematics 2016-12-13 Graziano Gentili , Anna Gori , Giulia Sarfatti

Denoting by $\mathbb{M}$ the complexification of the quaternionic algebra $\mathbb{H}$, we characterize the family of those $\mathbb{M}$-valued functions, defined on subsets of $\H$, whose values are actually quaternions, using an intrinsic…

Functional Analysis · Mathematics 2019-05-31 Florian-Horia Vasilescu

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

The papers \cite{O1,O2} are the first works to apply the theory of fiber bundles in the study of the quaternionic slice regular functions. The main goal of the present work is to extend the results given in \cite{O1}, where the quaternionic…

Complex Variables · Mathematics 2021-11-16 José Oscar González-Cervantes

A new class of regular quaternionic functions, defined by power series in a natural fashion, has been introduced in recent years. Several results of the theory recall the classical complex analysis, whereas other results reflect the…

Complex Variables · Mathematics 2011-02-15 G. Gentili , C. Stoppato

In this paper, we are concerned with the S-polyregularity the regular dot product of slice regular functions. We prove that the product of a slice regular function and right quaternionic polynomial function is a S-polyregular function and…

Complex Variables · Mathematics 2019-01-30 Allal Ghanmi

This work proposes a unified theory of regularity in one hypercomplex variable: the theory of $T$-regular functions. In the special case of quaternion-valued functions of one quaternionic variable, this unified theory comprises…

Complex Variables · Mathematics 2026-04-10 Riccardo Ghiloni , Caterina Stoppato

In this paper we provide a general construction of a quaternionic Banach space of slice regular functions from a given Banach space of holomorphic functions, which we call its quaternionic lift. To the best of our knowledge, this…

Functional Analysis · Mathematics 2025-12-09 Nikolaos Chalmoukis , Giulia Sarfatti

The sharp growth and distortion theorems are established for slice monogenic extensions of univalent functions on the unit disc $\mathbb D\subset \mathbb C$ in the setting of Clifford algebras, based on a new convex combination identity.…

Complex Variables · Mathematics 2017-01-17 Guangbin Ren , Xieping Wang

The aim of this paper is to obtain the Schwarz-Pick type inequality for $\alpha$-harmonic functions $f$ in the unit disk and get estimates on the coefficients of $f$. As an application, a Landau type theorem of $\alpha$-harmonic functions…

Complex Variables · Mathematics 2017-05-30 Peijin Li , Xiantao Wang , Qianhong Xiao

This work presents a family of fiber bundles where the total spaces are associated with holomorphic functions on several complex variables and the basis spaces extend the notion of quaternionic slice regular functions of several…

Complex Variables · Mathematics 2023-04-18 José Oscar González Cervantes