Besov空间中的一些最佳逼近与最佳逼近元之间的等价关系

Some equivalence relations between some best approximationsand some best approximate elements in the Besov space

在各类Besov空间中建立若干等价关系.文中的定理1是Cohen等人2000年论文中的定理4.2的实质性扩充,定理2将李松1997年论文中的定理7延拓到0<p≤∞时的情形.

This paper establishes some equivalence relations between some best approximations and some best approximate elements in various Besov spaces.Theorem 1 is an essential extension of Theorem 4.2 of the paper of Cohen, et al(2000) and Theorem 2 extends Theorem 7 of the paper of Li Song(1997) to the case 0<p≤∞.