论文标题
$ c^*$ - 代数的中心质质量和弱心性
The centre-quotient property and weak centrality for $C^*$-algebras
论文作者
论文摘要
我们为一般的$ c^*$ - 代数提供了许多等效条件(包括弱中心性),以具有中心质属性。我们表明,每个$ c^*$ - 代数$ a $都有最大的弱中心理想$ j_ {wc}(a)$。对于理想的$ i $ $ c^*$ - 代数$ a $,我们为中心元素$ a/$ a以$ a $ a $ a $ a $的中心元素的中心元素找到了必要且充分的条件。这导致了任意$ c^*$ - 代数$ a $的集合$ v_a $的表征,该元素可以防止$ a $具有中心质量属性。补充$ \ mathrm {cq}(a):= a \ setMinus v_a $总是包含$ z(a)+j_ {wc}(a)$(其中$ z(a)$是$ a $)的中心,仅当$ a/j_ {wc}(a)(a)$ abelian均为abelian。否则,$ \ mathrm {cq}(a)$失败了,是$ a $的$ c^*$ - subergebra。
We give a number of equivalent conditions (including weak centrality) for a general $C^*$-algebra to have the centre-quotient property. We show that every $C^*$-algebra $A$ has a largest weakly central ideal $J_{wc}(A)$. For an ideal $I$ of a unital $C^*$-algebra $A$, we find a necessary and sufficient condition for a central element of $A/I$ to lift to a central element of $A$. This leads to a characterisation of the set $V_A$ of elements of an arbitrary $C^*$-algebra $A$ which prevent $A$ from having the centre-quotient property. The complement $\mathrm{CQ}(A):= A \setminus V_A$ always contains $Z(A)+J_{wc}(A)$ (where $Z(A)$ is the centre of $A$), with equality if and only if $A/J_{wc}(A)$ is abelian. Otherwise, $\mathrm{CQ}(A)$ fails spectacularly to be a $C^*$-subalgebra of $A$.