【摘要】 <正> 稠性特征是Banach几何学中经常使用的重要概念,本文给出稠性特征的几种等价定义,并建立几个重要性质。定义1 设Ω是一个拓扑空间,Ω的所有稠子集的基数集中最小者叫做Ω的稠性特征,记作dens(Ω)。更多还原

【Abstract】 In this paper, we first give some equivalent definitions of density character of metric space which is convenient to determiner including the density character of some special spaces. Secondly, we establish the inequality dens~*(X~*)≤dens(X) and equality dens~w(X)=dens(X) for any Banach Space, from which we give some sufficient conditions, such as dens(X~*)=dens(X).更多还原