English

Convex polynomial approximation in $R^d$ with Freud weights

Classical Analysis and ODEs 2014-11-14 v3

Abstract

We show that for multivariate Freud-type weights Wα(x)=exp(xα)W_\alpha(x)=\exp(-|x|^\alpha), α>1\alpha>1, any convex function ff on RdR^d satisfying fWαLp(Rd)fW_\alpha\in L_p(R^d) if 1p<1\le p<\infty, or limxf(x)Wα(x)=0\lim_{|x|\to\infty}f(x)W_\alpha(x)=0 if p=p=\infty, can be approximated in the weighted norm by a sequence PnP_n of algebraic polynomials convex on RdR^d such that (fPn)WαLp(Rd)0\|(f-P_n)W_\alpha\|_{L_p(R^d)}\to0 as nn\to\infty. This extends the previously known result for d=1d=1 and p=p=\infty obtained by the first author to higher dimensions and integral norms using a completely different approach.

Keywords

Cite

@article{arxiv.1408.2131,
  title  = {Convex polynomial approximation in $R^d$ with Freud weights},
  author = {Oleksandr Maizlish and Andriy Prymak},
  journal= {arXiv preprint arXiv:1408.2131},
  year   = {2014}
}
R2 v1 2026-06-22T05:24:02.995Z