arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.00245math.FA
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Sobolev SpacesI嵌入常数问题中极值函数的显式

Explicit Form Of Extremal Functions In The Embedding Constant Problem For Sobolev SpacesI

Igor Sheipak, Tatiana Garmanova

摘要:

研究了索伯列夫空间$\mathring{W}^n_2[0;1] \hookrightarrow \mathring{W}^k_\infty[0; 1]$($0\leqslant k \leqslant n-1$)的嵌入常数.给出了嵌入常数与空间$\mathring{W}^n_2[0;1]$中泛函$f\mapsto f^{(k)}(a)$的范数之间的关系。找到了函数$g_{n;k}\in \mathring{W}^n_2[0;1]$的一个显式形式,这些泛函在该函数上达到其范数,并且这些函数对于嵌入常数也是极值的。给出了嵌入常数与勒让德多项式的关系。对k = 3和k = 5时的嵌入常数进行了详细的研究:得到了极值点的显式表达式,计算了全局极大值点,并给出了锐嵌入常数的值。发现了嵌入常数与一类具有分布系数的谱问题之间的联系。

英文摘要:

The embedding constants of the Sobolev spaces $\mathring{W}^n_2[0;1] \hookrightarrow \mathring{W}^k_\infty[0; 1]$ ($0\leqslant k \leqslant n-1$) are studied. A relation of the embedding constants with the norms of the functionals $f\mapsto f^{(k)}(a)$ in the space $\mathring{W}^n_2[0;1]$ is given. An explicit form of the functions $g_{n;k}\in \mathring{W}^n_2[0;1]$ on which these functionals attain their norm is found. These functions are also to be extremal for the embedding constants. A relation of the embedding constants to the Legendre polynomials is put forward. A detailed study is made of the embedding constants with k = 3 and k = 5: we found explicit formulas for extreme points, calculate global maximum points, and give the values of the sharp embedding constants. A link between the embedding constants and some class of spectral problems with distribution coefficients is discovered.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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