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Related papers: The $H^\infty$-functional calculi for the quaterni…

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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

we start the study of Schur analysis in the quaternionic setting using the theory of slice hyperholomorphic functions. The novelty of our approach is that slice hyperholomorphic functions allows to write realizations in terms of a suitable…

Functional Analysis · Mathematics 2011-10-13 Daniel Alpay , Fabrizio Colombo , Irene Sabadini

The $S$-functional calculus for slice hyperholomorphic functions generalizes the Riesz-Dunford-functional calculus for holomorphic functions to quaternionic linear operators and to $n$-tuples of noncommuting operators. For an unbounded…

Spectral Theory · Mathematics 2016-02-15 Jonathan Gantner

The spectral theory on the S-spectrum was introduced to give an appropriate mathematical setting to quaternionic quantum mechanics, but it was soon realized that there were different applications of this theory, for example, to fractional…

Spectral Theory · Mathematics 2022-05-18 Fabrizio Colombo , Antonino De Martino , Stefano Pinton , Irene Sabadini

In this paper, we present a new class of operators, which we name to be $n$-Ritt operators. This produces a discrete analogue of $n$-sectorial operators and generalizes the notion of Ritt operators. We develop a $H^\infty$-functional…

Functional Analysis · Mathematics 2017-09-19 Samya Kumar Ray

The present paper is a continuation of our work [11], where we introduced a fractional operator calculus related to a fractional ${\psi}-$Fueter operator in the one-dimensional Riemann-Liouville derivative sense in each direction of the…

Complex Variables · Mathematics 2022-09-27 José Oscar González-Cervantes , Juan Bory-Reyes

The fine structures on the $S$-spectrum constitute a new research area that includes a class of functional calculi based on the $S$-spectrum and on integral transforms determined by the Fueter--Sce mapping theorem and the Cauchy formula for…

Functional Analysis · Mathematics 2026-03-17 Fabrizio Colombo , Antonino De Martino , Joao Marques Da Costa

In this paper we study the additive splitting associated to the quaternionic Cauchy transform defined by the Cauchy formula of slice hyperholomorphic functions. Moreover, we introduce and study the analogue of the fundamental solution of…

Complex Variables · Mathematics 2019-01-30 Fabrizio Colombo , Samuele Mongodi

Quaternionic analysis offers a function theory focused on the concept of $\psi-$hyperholomorphic functions defined as null solutions of the $\psi-$Fueter operator, where $\psi$ is an arbitrary orthogonal base (called structural set) of…

Complex Variables · Mathematics 2021-11-10 José Oscar González-Cervantes , Juan Bory-Reyes

This paper deals with some special integral transforms of Bargmann-Fock type in the setting of quaternionic valued slice hyperholomorphic and Cauchy-Fueter regular functions. The construction is based on the well-known Fueter mapping…

Complex Variables · Mathematics 2019-10-02 Kamal Diki , Rolf Sören Krausshar , Irene Sabadini

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

This paper contributes to the recently introduced theory of fine structures on the $S$-spectrum. We study, in a unified way, the functional calculi for axially Poly-Analytic-Harmonic functions on the $S$-spectrum. Axially…

Functional Analysis · Mathematics 2026-02-05 F. Colombo , A. De Martino , S. Pinton

In this paper, we introduce the quaternionic slice polyanalytic functions and we prove some of their properties. Then, we apply the obtained results to begin the study of the quaternionic Fock and Bergman spaces in this new setting. In…

Complex Variables · Mathematics 2021-03-16 Daniel Alpay , Kamal Diki , Irene Sabadini

This paper is devoted to the multivariable $H^\infty$ functional calculus associated with a finite commuting family of sectorial operators on Banach space. First we prove that if $(A_1,\ldots, A_d)$ is such a family, if $A_k$ is…

Functional Analysis · Mathematics 2021-04-19 Olivier Arrigoni , Christian Le Merdy

The scalar functional determinants on sectors of the two-dimensional disc and spherical cap are determined for arbitrary angles (rational factors of $\pi$). The wholesphere and hemisphere expressions are also given, in low dimensions, for…

High Energy Physics - Theory · Physics 2009-10-22 J. S. Dowker

Let ${\cal{M}}$ be a complete Riemannian manifold with Ricci curvature bounded below and Laplace operator $\Delta$. The paper develops a functional calculus for the cosine family $\cos(t\sqrt {\Delta})$ which is associated with waves that…

Functional Analysis · Mathematics 2015-09-07 Gordon Blower , Ian Doust

This is an addition to a series of papers [FL1, FL2, FL3, FL4], where we develop quaternionic analysis from the point of view of representation theory of the conformal Lie group and its Lie algebra. In this paper we develop split…

Representation Theory · Mathematics 2015-06-23 Matvei Libine

The analogue of the Riesz-Dunford functional calculus has been introduced and studied recently as well as the theory of semigroups and groups of linear quaternionic operators. In this paper we suppose that $T$ is the infinitesimal generator…

Spectral Theory · Mathematics 2015-02-11 Daniel Alpay , Fabrizio Colombo , Jonathan Gantner , David P. Kimsey

Motivated by the general problem of extending the classical theory of holomorphic functions of a complex variable to the case of quater- nion functions, we give a notion of an H-derivative for functions of one quaternion variable. We show…

Complex Variables · Mathematics 2012-03-27 Omar Dzagnidze

In this paper we study Hankel operators in the quaternionic setting. In particular we prove that they can be exploited to measure the $L^{\infty}$ distance of a slice $L^{\infty}$ function from the space of bounded slice regular functions.

Complex Variables · Mathematics 2016-11-16 Giulia Sarfatti