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Related papers: Local approximation using Hermite functions

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We generalize the classical Bernstein theorem concerning the constructive description of classes of functions uniformly continuous on the real line. The approximation of continuous bounded functions by entire functions of exponential type…

Complex Variables · Mathematics 2008-03-11 Vladimir Andrievskii

We obtain order estimates of approximation of functions from the classes $S^{\Omega}_{p,\theta}B (\mathbb{R}^d)$ in the space $L_q(\mathbb{R}^d)$, $1<p<q<\infty$, by entire functions of exponential type with supports of their Fourier…

Classical Analysis and ODEs · Mathematics 2018-04-24 S. Ya. Yanchenko , S. A. Stasyuk

The aim of this paper is to construct sup-exponentially localized kernels and frames in the context of classical orthogonal expansions, namely, expansions in Jacobi polynomials, spherical harmonics, orthogonal polynomials on the ball and…

Classical Analysis and ODEs · Mathematics 2008-09-22 Kamen Ivanov , Pencho Petrushev , Yuan Xu

In this paper, we analyze the convergence behavior of Hermite-type sampling Kantorovich operators in the context of mixed norm spaces. We prove certain direct approximation theorems, including the uniform convergence theorem, the…

Functional Analysis · Mathematics 2025-06-04 Puja Sonawane , A. Sathish Kumar

Point source localisation is generally modelled as a Lasso-type problem on measures. However, optimisation methods in non-Hilbert spaces, such as the space of Radon measures, are much less developed than in Hilbert spaces. Most numerical…

Optimization and Control · Mathematics 2024-02-14 Tuomo Valkonen

Using a transference result, several inequalities of approximation by entire functions of exponential type in $\mathcal{C}(\mathbf{R})$, the class of bounded uniformly continuous functions defined on $\mathbf{R}:=\left( -\infty ,+\infty…

Classical Analysis and ODEs · Mathematics 2022-08-30 Ramazan Akgün

The Fourier coefficients of a smooth $K$-invariant function on a compact symmetric space $M=U/K$ are given by integration of the function against the spherical functions. For functions with support in a neighborhood of the origin, we…

Representation Theory · Mathematics 2010-02-23 Gestur Olafsson , Henrik Schlichtkrull

Highly localized kernels constructed by orthogonal polynomials have been fundamental in recent development of approximation and computational analysis on the unit sphere, unit ball and several other regular domains. In this work we first…

Classical Analysis and ODEs · Mathematics 2021-09-09 Yuan Xu

For many machine learning problem settings, particularly with structured inputs such as sequences or sets of objects, a distance measure between inputs can be specified more naturally than a feature representation. However, most standard…

Machine Learning · Statistics 2018-05-28 Lingfei Wu , Ian En-Hsu Yen , Fangli Xu , Pradeep Ravikumar , Michael Witbrock

We consider the global minimization of smooth functions based solely on function evaluations. Algorithms that achieve the optimal number of function evaluations for a given precision level typically rely on explicitly constructing an…

Optimization and Control · Mathematics 2020-12-23 Alessandro Rudi , Ulysse Marteau-Ferey , Francis Bach

In this paper local polynomials on Abelian groups are characterized by a "local" Fr\'echet-type functional equation. We apply our result to generalize Montel's Theorem and to obtain Montel-type theorems on commutative groups.

Functional Analysis · Mathematics 2014-03-19 J. M. Almira , L. Székelyhidi

We examine the necessary and sufficient complexity of neural networks to approximate functions from different smoothness spaces under the restriction of encodable network weights. Based on an entropy argument, we start by proving lower…

Functional Analysis · Mathematics 2020-09-21 Ingo Gühring , Mones Raslan

Kernel mean embedding is a useful tool to represent and compare probability measures. Despite its usefulness, kernel mean embedding considers infinite-dimensional features, which are challenging to handle in the context of differentially…

Machine Learning · Computer Science 2022-06-24 Margarita Vinaroz , Mohammad-Amin Charusaie , Frederik Harder , Kamil Adamczewski , Mijung Park

It is well known that approximation of functions on $[0,1]$ whose periodic extension is not continuous fail to converge uniformly due to rapid Gibbs oscillations near the boundary. Among several approaches that have been proposed toward the…

Numerical Analysis · Mathematics 2018-07-24 Akash Anand

We give a convergence proof for the approximation by sparse collocation of Hilbert-space-valued functions depending on countably many Gaussian random variables. Such functions appear as solutions of elliptic PDEs with lognormal diffusion…

Numerical Analysis · Mathematics 2017-03-29 Oliver G. Ernst , Björn Sprungk , Lorenzo Tamellini

We find two-sides estimates for the best uniform approximations of classes of convolutions of $2\pi$-periodic functions from unit ball of the space $L_p, 1 \le p <\infty,$ with fixed kernels, modules of Fourier coefficients of which satisfy…

Classical Analysis and ODEs · Mathematics 2020-08-05 A. S. Serdyuk , I. V. Sokolenko

We consider non-local elliptic operators with kernel $K(y)=a(y)/|y|^{d+\sigma}$, where $0 < \sigma < 2$ is a constant and $a$ is a bounded measurable function. By using a purely analytic method, we prove the continuity of the non-local…

Analysis of PDEs · Mathematics 2012-02-02 Hongjie Dong , Doyoon Kim

We establish asymptotic estimates for the least upper bounds of approximations in the uniform metric by Fourier sums of order $n-1$ of classes of $2\pi$-periodic Weyl--Nagy differentiable functions, $W^r_{\beta,p}, 1\le p\le \infty,…

Classical Analysis and ODEs · Mathematics 2022-02-08 A. S. Serdyuk , I. V. Sokolenko

We consider the space of functions almost in $L_p$ and endow it with the topology of asymptotic $L_p$-convergence. This yields a completely metrizable topological vector space which, on finite measure spaces, coincides with the space of…

Functional Analysis · Mathematics 2025-12-01 Nuno J. Alves

A basic problem of approximation theory, the approximation of functions from the Sobolev space W_p^r([0,1]^d) in the norm of L_q([0,1]^d), is considered from the point of view of quantum computation. We determine the quantum query…

Quantum Physics · Physics 2007-05-23 Stefan Heinrich