Sparse-grid sampling recovery and numerical integration of functions having mixed smoothness
Dinh Dũng
TL;DR
The paper surveys sparse-grid linear methods for recovering and integrating high-dimensional functions with mixed smoothness, focusing on unweighted Sobolev spaces on ${\mathbb T}^d$ and weighted spaces $W^r_p({\mathbb R}^d;\mu)$ with Freud-type and Gaussian measures. It develops B-spline quasi-interpolation representations and analyzes Smolyak sparse-grid algorithms, establishing asymptotic rates for linear sampling widths and identifying cases where Smolyak constructions are optimal. The text extends results to reproducing-kernel Hilbert spaces and discusses multiple notions of optimality in sampling recovery, revealing how width orders behave in different regimes of $p$, $q$, and dimension $d$. It then advances numerical weighted integration in these weighted Sobolev spaces, presenting assembling-based quadratures that achieve the right asymptotic orders for Freud-type weights and Gaussian measures, and addresses the particularly delicate $p=1$ case via sparse-grid and hyperbolic-cross strategies, including extensions to Markov–Sonin weights. Overall, the work provides a cohesive framework linking sparse-grid recovery and quadrature to the mixed-smoothness landscape, with concrete constructions and asymptotic guarantees across unweighted and weighted settings.
Abstract
We give a short survey of recent results on sparse-grid linear algorithms of approximate recovery and integration of functions possessing a unweighted or weighted Sobolev mixed smoothness based on their sampled values at a certain finite set. Some of them are extended to more general cases.
