English
Related papers

Related papers: Positive definite (p.d.) functions vs p.d. distrib…

200 papers

We compute Hermite expansions of some tempered distributions by using the Bargmann transform. In other words, we calculate the Taylor expansions of the corresponding entire functions. Our method of computations seems to be superior to the…

Classical Analysis and ODEs · Mathematics 2017-05-03 Hiroyuki Chihara , Takashi Furuya , Takumi Koshikawa

A new class of positive definite functions related to colour-length function on arbitrary Coxeter group is introduced. Extensions of positive definite functions, called the Riesz-Coxeter product, from the Riesz product on the Rademacher…

Operator Algebras · Mathematics 2018-08-01 Marek Bożejko , Światosław R. Gal , Wojciech Młotkowski

We develop a version of Herbrand's theorem for continuous logic and use it to prove that definable functions in infinite-dimensional Hilbert spaces are piecewise approximable by affine functions. We obtain similar results for definable…

Logic · Mathematics 2011-07-20 Isaac Goldbring

We develop a theory of partially defined complete positivity preservers, extending Schoenberg's classical characterization to functions defined only on discrete subsets or constrained domains. We frame the extension problem through the…

Functional Analysis · Mathematics 2026-02-10 Sujit Sakharam Damase , James Eldred Pascoe

We introduce the notion of Dunkl positive definite and strictly positive definite functions on $\mathbb{R}^{d}$. This done by the use of the properties of Dunkl translation. We establish the analogue of Bochner's theorem in Dunkl setting.…

Classical Analysis and ODEs · Mathematics 2013-06-04 Jamel El Kamel , Khaled Mehrez

We extend the construction of [19] by introducing spaces of generalized tensor fields on smooth manifolds that possess optimal embedding and consistency properties with spaces of tensor distributions in the sense of L. Schwartz. We thereby…

Functional Analysis · Mathematics 2012-05-31 Michael Grosser , Michael Kunzinger , Roland Steinbauer , James Vickers

We define embedding of an $n$-dimensional normed space into $L_{-p},\ 0<p<n$ by extending analytically with respect to $p$ the corresponding property of the classical $L_p$-spaces. The well-known connection between embeddings into $L_p$ and…

Functional Analysis · Mathematics 2016-09-06 Alexander Koldobsky

With view to applications, we establish a correspondence between two problems: (i) the problem of finding continuous positive definite extensions of functions $F$ which are defined on open bounded domains $\Omega$ in $\mathbb{R}$, on the…

Functional Analysis · Mathematics 2015-06-19 Palle Jorgensen , Feng Tian

We present the construction of a theory of distributions (generalized functions) with a ``thick submanifold'', that is, a new theory of thick distributions on $\mathbb{R}^n$ whose domain contains a smooth submanifold on which the test…

Functional Analysis · Mathematics 2025-10-27 Jiajia Ding , Jasson Vindas , Yunyun Yang

We introduce $p$-adic Kummer spaces of continuous functions on $\mathbb{Z}_p$ that satisfy certain Kummer type congruences. We will classify these spaces and show their properties, for instance, ring properties and certain decompositions.…

Number Theory · Mathematics 2009-10-07 Bernd C. Kellner

We generalize the notion of harmonic conjugate functions and Hilbert transforms to higher dimensional euclidean spaces, in the setting of differential forms and the Hodge-Dirac system. These conjugate functions are in general far from being…

Analysis of PDEs · Mathematics 2009-05-01 Andreas Axelsson , Kit Ian Kou , Tao Qian

We give a local characterization of the class of functions having positive distributional derivative with respect to $\bar{z}$ that are almost everywhere equal to one of finitely many analytic functions and satisfy some mild non-degeneracy…

Complex Variables · Mathematics 2009-09-29 Julius Borcea , Rikard Bøgvad

We present some remarks about the embedding of spaces of Schwartz distributions into spaces of Colombeau generalized functions. We show that the various constructions of such embeddings existing in the literature lead in fact to the same…

Functional Analysis · Mathematics 2007-06-13 A. Delcroix

We generalise the result of Berger and Shaw the trace formula for Hardy Hilbert space to a larger class of rotation invariant Hilbert function spaces on the unit disk. We also demonstrate many meaningful examples of these Hilbert spaces by…

Functional Analysis · Mathematics 2025-08-06 Nathan Parker

In a general context of positive definite kernels $k$, we develop tools and algorithms for sampling in reproducing kernel Hilbert space $\mathscr{H}$ (RKHS). With reference to these RKHSs, our results allow inference from samples; more…

Functional Analysis · Mathematics 2016-01-28 Palle Jorgensen , Feng Tian

Based on direct integrals, a framework allowing to integrate a parametrised family of reproducing kernels with respect to some measure on the parameter space is developed. By pointwise integration, one obtains again a reproducing kernel…

Functional Analysis · Mathematics 2012-02-21 Thomas Hotz , Fabian J. E. Telschow

We present a systematic study of the family of positive definite (p.d.) kernels with the use of their associated feature maps and feature spaces. For a fixed set $X$, generalizing Loewner, we make precise the corresponding partially ordered…

Functional Analysis · Mathematics 2025-01-22 Palle E. T. Jorgensen , James Tian

We consider Hilbert spaces of analytic functions in the disk with a normalized reproducing kernel and such that the backward shift $f(z) \mapsto \frac{f(z)-f(0)}{z}$ is a contraction on the space. We present a model for this operator and…

Functional Analysis · Mathematics 2019-01-15 Alexandru Aleman , Bartosz Malman

We provide necessary and sufficient conditions for a tempered distribution $F\in S'(R)$ to be positive definite. A generalized Cauchy transform $\widetilde{F}$ of $F$ is used as a numerical continuation of $F$ to the open upper and lower…

Functional Analysis · Mathematics 2020-09-08 Saulius Norvidas

These notes briefly consider convolutions of tempered distributions with functions in the Schwartz class.

Classical Analysis and ODEs · Mathematics 2007-05-23 Stephen Semmes