摘要
令M1为一个有限的von Neumann代数,τ1为其上的一个忠实正规迹态.我们将证明,如果M1中存在一列两两正交的酉元列{uk:k∈N},则对任意具有忠实正规迹态τ2的有限von Neumann代数M2(≠C),迹自由积(M1,τ1)*(M2,τ2)是Ⅱ1型因子.作为推论可以得出,如果M1有一个von Neumann子代数N不包含最小投影,则对任意具有忠实迹态τ2的有限von Neumann代数M2(≠C),迹自由积(M1,τ1)*(M2,τ2)是Ⅱ1型因子.
Let M1 be a finite von Neumann algebra with a faithful normal trace τ1 and let M1o={a ∈ M,τ1(a)=0}. We prove that, if there is a sequence {uk:k ∈ M } of orthogonal unitaries in M1o, then for any finite von Neumann algebra M2(≠C) with a faithful normal trace τ2, the tracial free product (M1, τ1) * (M2, τ2) is a type Ⅱ1 factor. As a corollary, we obtain that, if there is a von Neumann subalgebra N of M1 such that N has no minimal projection, then for any finite von Neumann algebra M2(≠ C) with a faithful normal trace τ2, the tracial free product (M1, τ1) * (M2, τ2) is a type Ⅱ1 factor.
作者
佐凯悦
钱文华
Kai Yue ZUO;Wen Hua QIAN(School of Mathematical Sciences,Chongqing Normal University,Chongqing 401331,P.R.China)
出处
《数学学报(中文版)》
CSCD
北大核心
2018年第6期1021-1028,共8页
Acta Mathematica Sinica:Chinese Series
基金
国家自然科学基金资助项目(11671133)
关键词
正交酉元列
迹自由积
Ⅱ_1型因子
sequence of orthogonal unitaries
tracial free product
type Ⅱ1 factor