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Related papers: Data Assimilation and Sampling in Banach spaces

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In this paper we continue to develop the following general approach. We study asymptotic behavior of the errors of sampling recovery not for an individual smoothness class, how it is usually done, but for the collection of classes, which…

Numerical Analysis · Mathematics 2026-01-14 V. Temlyakov

We propose a new numerical scheme for approximating level-sets of Lipschitz multivariate functions which is robust to stochastic noise. The algorithm's main feature is an adaptive grid-based stochastic approximation strategy which…

Numerical Analysis · Mathematics 2025-09-19 Matteo Croci , Abdul-Lateef Haji-Ali , Ian C. J. Powell

Our work is related to problems $73$ and $74$ of Mazur and Orlicz in ``The Scottish Book" (ed. R. D. Mauldin). Let $k_1, \ldots, k_n$ be nonnegative integers such that $\sum_{i=1}^{n} k_{i}=m$, and let $\mathbb{K}(k_1, \ldots, k_n; X)$,…

Functional Analysis · Mathematics 2021-07-14 Marianna Chatzakou , Yannis Sarantopoulos

We study optimal algorithms in adaptive sampling recovery of smooth functions defined on the unit $d$-cube ${\II}^d:= [0,1]^d$. The recovery error is measured in the quasi-norm $\|\cdot\|_q$ of $L_q := L_q(\II^d)$. For $B$ a subset in…

Functional Analysis · Mathematics 2011-03-01 Dinh Dũng

We provide sufficient conditions on a family of functions $(\phi_\alpha)_{\alpha\in A}:\mathbb{R}^d\to\mathbb{R}$ for sampling of multivariate bandlimited functions at certain nonuniform sequences of points in $\mathbb{R}^d$. We consider…

Functional Analysis · Mathematics 2018-02-14 Keaton Hamm

We develop Banach spaces for ReLU neural networks of finite depth $L$ and infinite width. The spaces contain all finite fully connected $L$-layer networks and their $L^2$-limiting objects under bounds on the natural path-norm. Under this…

Machine Learning · Statistics 2020-07-31 Weinan E , Stephan Wojtowytsch

Proximal gradient methods are a popular tool for the solution of structured, nonsmooth minimization problems. In this work, we investigate an extension of the former to general Banach spaces and provide worst-case convergence rates for,…

Optimization and Control · Mathematics 2025-09-30 Gerd Wachsmuth , Daniel Walter

We study two types of approximations of Lipschitz maps with derivatives of maximal slopes on Banach spaces. First, we characterize the Radon-Nikod\'ym property in terms of strongly norm attaining Lipschitz maps and maximal derivative…

Functional Analysis · Mathematics 2024-10-23 Geunsu Choi

We obtain new sampling discretization results in Orlicz norms on finite dimensional spaces. As applications, we study sampling recovery problems, where the error of the recovery process is calculated with respect to different Orlicz norms.…

Functional Analysis · Mathematics 2024-08-27 Egor Kosov , Sergey Tikhonov

This paper is devoted to the study of the relatively compact sets in Quasi-Banach function spaces, providing an important improvement of the known results. As an application, we take the final step in establishing a relative compactness…

Classical Analysis and ODEs · Mathematics 2020-06-24 Weichao Guo , Guoping Zhao

Let $X$ be a Banach holomorphic function space on the unit disk. A linear polynomial approximation scheme for $X$ is a sequence of bounded linear operators $T_n:X\to X$ with the property that, for each $f\in X$, the functions $T_n(f)$ are…

Functional Analysis · Mathematics 2020-11-09 Javad Mashreghi , Thomas Ransford

In this paper, the problem of the order of approximation for the multivariate sampling Kantorovich operators is studied. The cases of the uniform approximation for uniformly continuous and bounded functions/signals belonging to Lipschitz…

Functional Analysis · Mathematics 2014-11-11 Danilo Costarelli , Gianluca Vinti

Recently, versions of neural networks with infinite-dimensional affine operators inside the computational units (``neural operator'' networks) have been applied to learn solutions to differential equations. To enable practical computations,…

Functional Analysis · Mathematics 2026-02-03 Vinícius Luz Oliveira , Vladimir G. Pestov

Let X and Y be separable metrizable spaces, and f:X-->Y be a function. We want to recover f from its values on a small set via a simple algorithm. We show that this is possible if f is Baire class one, and in fact we get a characterization.…

Logic · Mathematics 2007-10-02 Dominique Lecomte

In this erratum, we recover the results from an earlier paper of the author's which contained a gap. Specifically, we prove that if X is a Banach space with an unconditional basis and admits a C^{p}-smooth, Lipschitz bump function, and Y is…

Functional Analysis · Mathematics 2015-05-13 R. Fry

Consider a nonlinear ill-posed operator equation $F(u)=y$ where $F$ is defined on a Banach space $X$. In general, for solving this equation numerically, a finite dimensional approximation of $X$ and an approximation of $F$ are required.…

Numerical Analysis · Mathematics 2015-05-18 C. Poeschl , E. Resmerita , O. Scherzer

For a Banach space $B$ of functions which satisfies for some $m>0$ $$ \max(\|F+G\|_B,\|F-G\|_B) \ge (\|F\|^s_B + m\|G\|^s_B)^{1/s}, \forall F,G\in B \ (*) $$ a significant improvement for lower estimates of the moduli of smoothness…

Classical Analysis and ODEs · Mathematics 2014-03-17 Zeev Ditzian , Andriy Prymak

Let $X$ be a real separable normed space $X$ admitting a separating polynomial. We prove that each continuous function from a subset $A$ of $X$ to a real Banach space can be uniformly approximated by restrictions to $A$ of functions which…

Functional Analysis · Mathematics 2020-04-03 M. A. Mytrofanov , A. V. Ravsky

We study best approximations in Banach spaces via Birkhoff-James orthogonality of functionals. To exhibit the usefulness of Birkhoff-James orthogonality techniques in the study of best approximation problems, some algorithms and distance…

Functional Analysis · Mathematics 2021-04-30 Debmalya Sain , Saikat Roy

We provide a comprehensive study of interrelations between different measures of smoothness of functions on various domains and smoothness properties of approximation processes. Two general approaches to this problem have been developed:…

Classical Analysis and ODEs · Mathematics 2020-03-18 Yu. Kolomoitsev , S. Tikhonov