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Related papers: Boundary Julia theory for slice regular functions

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We prove a sharp version of the Hopf boundary point lemma for Black-Scholes type equations. We also investigate the existence and the regularity of the spatial derivative of the solutions at the spatial boundary.

Analysis of PDEs · Mathematics 2008-12-02 Erik Ekström , Johan Tysk

This paper addresses the Corona problem for slice hyperholomorphic functions for a single quaternionic variable. While the Corona problem is well-understood in the context of one complex variable, it remains highly challenging in the case…

Complex Variables · Mathematics 2025-08-28 Fabrizio Colombo , Elodie Pozzi , Irene Sabadini , Brett D. Wick

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

The Julia quotient measures the ratio of the distance of a function value from the boundary to the distance from the boundary. The Julia-Carath\'eodory theorem on the bidisk states that if the Julia quotient is bounded along some sequence…

Complex Variables · Mathematics 2016-10-07 John E. McCarthy , James E. Pascoe

In this paper we prove a new representation formula for slice regular functions, which shows that the value of a slice regular function $f$ at a point $q=x+yI$ can be recovered by the values of $f$ at the points $q+yJ$ and $q+yK$ for any…

Complex Variables · Mathematics 2010-03-30 Fabrizio Colombo , Graziano Gentili , Irene Sabadini , Daniele C. Struppa

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

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

Entire functions in one complex variable are extremely relevant in several areas ranging from the study of convolution equations to special functions. An analog of entire functions in the quaternionic setting can be defined in the slice…

Complex Variables · Mathematics 2016-11-08 Fabrizio Colombo , Irene Sabadini , Daniele C. Struppa

In this paper we introduce fractional powers of quaternionic operators. Their definition is based on the theory of slice-hyperholomorphic functions and on the $S$-resolvent operators of the quaternionic functional calculus. The integral…

Functional Analysis · Mathematics 2016-05-24 Fabrizio Colombo , Jonathan Gantner

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

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

In this paper we develop the theory of Schauder estimates for the fractional harmonic oscillator $H^\sigma=(-\Delta+|x|^2)^\sigma$, $0<\sigma<1$. More precisely, a new class of smooth functions $C^{k,\alpha}_H$ is defined, in which we study…

Analysis of PDEs · Mathematics 2011-02-08 P. R. Stinga , J. L. Torrea

This works introduces several notions of subharmonicity for real-valued functions of one quaternionic variable. These notions are related to the theory of slice regular quaternionic functions introduced by Gentili and Struppa in 2006. The…

Complex Variables · Mathematics 2019-11-05 Caterina Stoppato

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

Slice-regular functions of a quaternionic variable have been studied extensively in the last 12 years, resulting, in many ways, quite close to classical holomorphic functions of a complex variable; indeed, there is a correspondence between…

Complex Variables · Mathematics 2018-07-23 Samuele Mongodi

Let $f: D \rightarrow \Omega$ be a complex analytic function. The Julia quotient is given by the ratio between the distance of $f(z)$ to the boundary of $\Omega$ and the distance of $z$ to the boundary of $D.$ A classical…

Functional Analysis · Mathematics 2018-09-26 J. E. Pascoe , Meredith Sargent , Ryan Tully-Doyle

The most classical version of the Schwarz lemma involves the behavior at the origin of a bounded, holomorphic function on the disc. Pick's version of the Schwarz lemma allows one to move the origin to other points of the disc. In the…

Complex Variables · Mathematics 2010-01-13 Steven G. Krantz

The abstract theory of boundary triples is applied to the classical Jacobi differential operator and its powers in order to obtain the Weyl $m$-function for several self-adjoint extensions with interesting boundary conditions: separated,…

Functional Analysis · Mathematics 2019-11-22 Dale Frymark

In this paper, we consider different versions of the classical Hopf's boundary lemma in the setting of the fractional $p-$Laplacian for $p \geq 2$. We start by providing for a new proof to a Hopf's lemma based on comparison principles.…

Analysis of PDEs · Mathematics 2024-11-08 Pablo Ochoa , Ariel Salort