This article is cited in 2 papers

Extremal cubature formulas for anisotropic classes

V. A. Bykovskii

Khabarovsk Division of the Institute for Applied Mathematics, Far Eastern Branch, Russian Academy of Sciences

Abstract: Let $E^{(\alpha; s)}$ be a class of periodical functions
$$ f(x_1, \dots, x_s)=\sum_{(m_1, \dots, m_s)\in \mathbb{Z}^s} c(m_1, \dots, m_s)\exp\left(2\pi i(m_1 x_1+\dots+ m_s x_s)\right) $$
with $ \left|c(m_1, \dots, m_s)\right|\leq \prod_{j=1} \left(\text{max} (1, |m_j|)\right)^{-\alpha}, $ and $1< \alpha < \infty$. In this work for all natural numbers $1< N < \infty$ we prove best possible estimation
$$ R_N\left(E^{(\alpha; s)}\right)\ll_{\alpha, s} \frac{\left(\log N\right)^{s-1}}{N^\alpha} $$
for the error of the best cubature formula on the class $E^{(\alpha; s)}$ with $N$ nodes and weights. Similar results are proved for other classes of functions.

Key words: cubature formulas, anisotropic classes of functions.

UDC: 519.68

MSC: 65J01

Received: 21.05.2019