R~n空间中单位球面的极小球覆盖

Abstract

考虑如下问题:对一个Banach空间X,已知其单位球面SX可以被n+1个不含原点为其内点的闭球所覆盖,则其最小覆盖半径是多少?本文针对一特殊空间Rn,首先证明了在Rn中,若有一点集{xi}im=1满足一定条件,则可给出一特殊的球覆盖,且此覆盖的半径即为最小半径.进一步本文还给出了在Rn中若任意给定r≥32,可找到一个以r为覆盖半径的球覆盖,且此覆盖的势为极小的.

Considering the following problem: for a Banach space X with dimX=n,it has already known that the sphere of the unit ball of X can be covered by a ball-covering of n+1 closed balls not containing the origin in its interior,then what is its smallest radius? This article first proves that there exists a specific ball-covering with the smallest radius in R~n if a set {x_i}~m_(i=1) satisfying some given term,then presents a minimal ball-covering with arbitrary given r≥32 as its radius.