用指数型整函数的最佳限制逼近

凌博, 刘永平

数学学报 ›› 2017, Vol. 60 ›› Issue (3) : 389-400.

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数学学报 ›› 2017, Vol. 60 ›› Issue (3) : 389-400. DOI: 10.12386/A2017sxxb0032
论文

用指数型整函数的最佳限制逼近

    凌博1, 刘永平2
作者信息 +

Best Restriction Approximation by Entire Functions of Exponential Type

    Bo LING1, Yong Ping LIU2
Author information +
文章历史 +

摘要

我们研究了由仅有实零点的代数多项式导出的微分算子确定的广义Sobolev类利用指数型整函数作为逼近工具的最佳限制逼近问题.利用Fourier变换和周期化等方法,得到在L2(R)范数下的广义Sobolev光滑函数类的相对平均宽度和最佳限制逼近的精确常数,以及当0是这个代数多项式的一个至多2重的零点时,得到最佳限制逼近在L1(R)范数和一致范数下的广义Sobolev类的精确到阶的结果.

Abstract

We studied the best restriction approximation problems using entire functions of exponential type as the approximation tools on some generalized Sobolev classes of smooth functions defined by the differential operator induced by an algebraic polynomial with only real zeros. By the methods of Fourier transform and periodization, etc, we obtained the exact constants of the average relative widths and the best restriction approximation on the generalized Sobolev classes in the L2(R) norm, and obtained the asymptotic results of the best restriction approximation on the generalized Sobolev classes in the L1(R) norm and the uniform norm for the case that the polynomial has a zero of multiplicity at most 2 at the point 0.

关键词

最佳限制逼近 / 相对平均宽度 / 指数型整函数

Key words

restriction approximation / relative width / entire function

引用本文

导出引用
凌博, 刘永平. 用指数型整函数的最佳限制逼近. 数学学报, 2017, 60(3): 389-400 https://doi.org/10.12386/A2017sxxb0032
Bo LING, Yong Ping LIU. Best Restriction Approximation by Entire Functions of Exponential Type. Acta Mathematica Sinica, Chinese Series, 2017, 60(3): 389-400 https://doi.org/10.12386/A2017sxxb0032

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基金

国家自然科学基金资助项目(11401451,11471043)

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