Bernstein inequality for multivariate functions with smooth Fourier images

Authors

  • Ha Huy Bang Inst. Math., Vietnam Acad. Sci. and Technology, Hanoi, Vietnam
  • Vu Nhat Huy Hanoi Univ. Sci., Vietnam Nat. Univ., and TIMAS, Thang Long Univ., Hanoi, Vietnam

DOI:

https://doi.org/10.37863/umzh.v74i11.6386

Keywords:

Lp- spaces, Bernstein inequality, generalized functions

Abstract

UDC 517.5

Let K be a compact set in Rn with (O)-property and let 1p. Then there exists a constant CK< independent of f and α such that  for all \alpha \in \mathbb{Z}_+^n and f\in \mathcal{H}_{p,K,3}, where \mathcal{H}_{p,K,3}=\big\{f \in L^p({\Bbb R}^n)\colon {\rm supp\,} \widehat f \subset K ,D^{(3,3,\ldots,3)} \widehat{f} \in C({\Bbb R}^n) \big\}, \|f\|_{\mathcal{H}_{p,K,3}} = \big\|D^{(3,3,\ldots,3)} \widehat{f}\,\big\|_\infty, and \widehat{f} is the Fourier transform of f. Note that K is said to have the (O)-property if there exists a constant C>0 such that \sup\limits_{{\bf x} \in K} |{\bf x}^{\alpha + e_j} | \geq C\sup\limits_{{\bf x} \in K } |{\bf x}^{\alpha} | for all \alpha \in \mathbb{Z}_+^n and j=1,2, \ldots ,n.

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Published

26.12.2022

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Section

Research articles

How to Cite

Bang, Ha Huy, and Vu Nhat Huy. “Bernstein Inequality for Multivariate Functions With Smooth Fourier Images”. Ukrains’kyi Matematychnyi Zhurnal, vol. 74, no. 11, Dec. 2022, pp. 1558-70, https://doi.org/10.37863/umzh.v74i11.6386.