本文研究了定向集指标非交换鞅的几种收敛性.利用非交换鞅的理论,得到了如下结果:设{xα,Mα}α∈I是一个定向集指标的非交换鞅.则{xα}依L^1范数收敛(或弱收敛)的充要条件是{xα}一致可积且满足条件(B):对任意的ε〉0,存在投影e∈M,使得对任意的y∈M,||y||≤1及任意的α∈I,有|τ(exαey)|〈ε.当1〈p〈∞时,{xα)依L^p范数收敛(或弱收敛)的充要条件是{xα)在L^p(M)中依L^p范数有界.这也等价于存在一个x∞∈L^p(M),使得xα=∈α(x∞)(α∈I).推广了交换情形中的相应结果.
In this paper, we discuss the convergence of noncommutative martingales indexed by directed sets. According to the theory of noncommutative martingales, we come to the following conclusions: Let {xα, Mα}α∈Ibe a noncommutative martingale with a directed index set. Then{xα} converges in L1-norm(or weakly) if and only if {xα} is uniformly integrable and satisfies the condition(B): for each ε 0 there is a projection e ∈ M such that |τ(exαey)|〈 ε for any y ∈ M, ||y|| ≤ 1 and any α ∈ I. When 1 〈p 〈∞, {xα} converges in Lp-norm(or weakly) if and only if{xα} is Lp-bounded in Lp(M). It is also equivalent to that there exists an x∞∈ Lp(M) such that xα= Eα(x∞)(α ∈ I). It generalizes the corresponding conclusions in the commutative condition.