<p>We obtain sharp inequalities for the best mean square approximation of two classes of functions on the half-line, defined by boundary conditions corresponding to even and odd extension of a function. Optimal subspaces are provided by even and odd parts of the spaces generated by equidistant shifts of a single function. Under certain additional conditions on this function, the sharpness of the inequalities in the sense of average widths is proved. Bibliography: 9 titles.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

OPTIMAL SUBSPACES FOR MEAN SQUARE APPROXIMATION OF CLASSES OF DIFFERENTIABLE FUNCTIONS ON THE HALF-LINE

  • O. L. Vinogradov,
  • A. Yu. Ulitskaya

摘要

We obtain sharp inequalities for the best mean square approximation of two classes of functions on the half-line, defined by boundary conditions corresponding to even and odd extension of a function. Optimal subspaces are provided by even and odd parts of the spaces generated by equidistant shifts of a single function. Under certain additional conditions on this function, the sharpness of the inequalities in the sense of average widths is proved. Bibliography: 9 titles.