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Related papers: Fock and Hardy spaces: Clifford-Appell case

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Quaternionic representations of Coxeter (reflection) groups of ranks 3 and 4, as well as those of E_8, have been used extensively in the literature. The present paper analyses such Coxeter groups in the Clifford Geometric Algebra framework,…

Mathematical Physics · Physics 2013-07-26 Pierre-Philippe Dechant

In this paper, a fractional version of the Clifford-Fourier transform is introduced, depending on two numerical parameters. A series expansion for the kernel of the resulting integral transform is derived. In the case of even dimension,…

Classical Analysis and ODEs · Mathematics 2012-09-27 Hendrik De Bie , Nele De Schepper

In this paper, we make the case that Clifford algebra is the natural framework for root systems and reflection groups, as well as related groups such as the conformal and modular groups: The metric that exists on these spaces can always be…

Mathematical Physics · Physics 2016-02-22 Pierre-Philippe Dechant

In this paper, we study the generalized Clifford-Fourier transform introduced in [6] using the Laplace transform technique. We give explicit expressions in the even dimensional case, we obtain polynomial bounds for the kernel functions and…

Classical Analysis and ODEs · Mathematics 2016-11-02 Pan Lian , Gejun Bao , Hendrik De Bie , Denis Constales

In the Clifford algebra setting the present study develops three reproducing kernel Hilbert spaces of the Paley-Wiener type, namely the Paley-Wiener spaces, the Hardy spaces on strips, and the Bergman spaces on strips. In particular, we…

Complex Variables · Mathematics 2021-08-31 Pei Dang , Weixiong Mai , Tao Qian

These notes are intended as a fairly self contained explanation of Fock space and various algebras that act on it, including a Clifford algebra, a Weyl algebra, an infinite rank matrix algebra, and an affine Kac-Moody algebra. We also…

Representation Theory · Mathematics 2023-10-18 Peter Tingley

We study mapping properties of operators with kernels defined via a combination of continuous and discrete orthogonal polynomials, which provide an abstract formulation of quantum (q-) Fourier type systems. We prove Ismail conjecture…

Classical Analysis and ODEs · Mathematics 2007-05-23 Luis Daniel Abreu

Inspired from the Cholewinski approach see [5], we investigate a family of Fock spaces in the quaternionic slice hyperholomorphic setting as well as some associated quaternionic linear operators. In a particular case, we reobtain the slice…

Complex Variables · Mathematics 2019-05-01 Kamal Diki

We introduce a complex-valued counterpart of the representer theorem in machine learning. We study several learning and minimization problems in reproducing kernel Hilbert spaces (RKHSs), with the aim of identifying appropriate input-output…

Functional Analysis · Mathematics 2026-04-28 Natanael Alpay , Antonino De Martino , Kamal Diki

We develop some aspects of the theory of hyperholomorphic functions whose values are taken in a Banach algebra over a field -- assumed to be the real or the complex numbers -- and which contains the field. Notably, we consider Fueter…

Functional Analysis · Mathematics 2018-12-19 Daniel Alpay , Ismael L. Paiva , Daniele C. Struppa

CLIFFORD performs various computations in Grassmann and Clifford algebras. It can compute with quaternions, octonions, and matrices with entries in Cl(B) - the Clifford algebra of a vector space V endowed with an arbitrary bilinear form B.…

Mathematical Physics · Physics 2013-01-14 Rafal Ablamowicz , Bertfried Fauser

We study the algebra of complex polynomials which remain invariant under the action of the local Clifford group under conjugation. Within this algebra, we consider the linear spaces of homogeneous polynomials degree by degree and construct…

Quantum Physics · Physics 2009-11-10 Maarten Van den Nest , Jeroen Dehaene , Bart De Moor

Several versions of the Fourier transform have been formulated in the framework of Clifford algebra. We present a (Clifford-Fourier) transform, constructed using the geometric properties of Clifford algebra. We show the corresponding…

Functional Analysis · Mathematics 2014-05-27 Arnoldo Bezanilla Lopez , Omar Leon Sanchez

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

Recently, there has been an increasing interest in the study of hypercomplex signals and their Fourier transforms. This paper aims to study such integral transforms from general principles, using 4 different yet equivalent definitions of…

Classical Analysis and ODEs · Mathematics 2011-01-11 H. De Bie , N. De Schepper , F. Sommen

We propose a mathematical framework that we call quantum, higher-order Fourier analysis. This generalizes the classical theory of higher-order Fourier analysis, which led to many advances in number theory and combinatorics. We define a…

Quantum Physics · Physics 2025-09-09 Kaifeng Bu , Weichen Gu , Arthur Jaffe

Multi-norm singular integrals and Fourier multipliers were introduced in [29], and one application of these notions was a precise description of the composition of convolution operators with Calder\'on-Zygmund kernels adapted to $n$…

Functional Analysis · Mathematics 2025-07-15 Agnieszka Hejna , Alexander Nagel , Fulvio Ricci

Clifford-Legendre and Clifford-Gegenbauer polynomials are eigenfunctions of certain differential operators acting on functions defined on $m$-dimensional euclidean space ${\mathbb R}^m$ and taking values in the associated Clifford algebra…

Classical Analysis and ODEs · Mathematics 2020-12-11 Hamed Baghal Ghaffari , Jeffrey A. Hogan , Joseph D. Lakey

We study a new class of functions that arise naturally in quaternionic analysis, we call them "quasi regular functions". Like the well-known quaternionic regular functions, these functions provide representations of the quaternionic…

Representation Theory · Mathematics 2026-01-26 Igor Frenkel , Matvei Libine

We study kernel functions, and associated reproducing kernel Hilbert spaces $\mathscr{H}$ over infinite, discrete and countable sets $V$. Numerical analysis builds discrete models (e.g., finite element) for the purpose of finding…

Functional Analysis · Mathematics 2015-08-17 Palle Jorgensen , Feng Tian