Approximation by normal elements with finite spectra in C*-algebras of real rank zero

被引:50
作者
Lin, HX
机构
[1] Department of Mathematics, University of Oregon, Eugene
关键词
D O I
10.2140/pjm.1996.173.443
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
We study the problem when a normal element in a C*-algebra of real rank zero can be approximated by normal elements with finite spectra. We show that all purely infinite simple C*-algebras, irrational rotation algebras and some types of C*-algebras of inductive limit of the form C(X) x M(n) of real rank zero have the property weak (FN), i.e., a normal element x can be approximated by normal elements with finite spectra if and only if Gamma(x) = 0 (lambda-x is an element of In v(0)(A) for all lambda is not an element of sp(x)). For general C*-algebras with real rank zero, we show that a normal element x with dim sp(x) less than or equal to 1 can be approximated by normal elements with finite spectra if and only if Gamma(x) = 0. One immediate application is that if A is a simple C*-algebra with real rank zero which is an inductive limit of C*-algebras Of form C(X(n)) x M(m(n)), where each X(n) is a compact subset of the plane, then A is an AF-algebra if and only if K-1 (A) = 0.
引用
收藏
页码:443 / 489
页数:47
相关论文
共 51 条
[1]  
Alfsen E M., 1971, Ergebnisse der Mathematik und ihrer Grenzgebiete
[2]  
[Anonymous], 1986, MATH SURVEYS MONOGR
[3]   ALMOST COMMUTING MATRICES AND A QUANTITATIVE VERSION OF THE BROWN-DOUGLAS-FILLMORE THEOREM [J].
BERG, ID ;
DAVIDSON, KR .
ACTA MATHEMATICA, 1991, 166 (1-2) :121-161
[4]   THE REAL RANK OF INDUCTIVE LIMIT C-ASTERISK-ALGEBRAS [J].
BLACKADAR, B ;
DADARLAT, M ;
RORDAM, M .
MATHEMATICA SCANDINAVICA, 1991, 69 (02) :211-216
[5]   REDUCTION OF REAL RANK IN INDUCTIVE LIMITS OF C-ALGEBRAS [J].
BLACKADAR, B ;
BRATTELI, O ;
ELLIOTT, GA ;
KUMJIAN, A .
MATHEMATISCHE ANNALEN, 1992, 292 (01) :111-126
[6]  
Blackadar B., 1992, K-THEORY, V6, P267, DOI DOI 10.1007/BF00961466
[7]  
Blackadar B., 1986, K THEORY OPERATOR AL, V5, DOI 10.1007/978-1-4613-9572-0
[8]   TRACES ON SIMPLE AF CSTAR-ALGEBRAS [J].
BLACKADAR, BE .
JOURNAL OF FUNCTIONAL ANALYSIS, 1980, 38 (02) :156-168
[9]  
BLACKADER B, 1982, NOTES STRUCTURE PROJ
[10]  
BRATTELI O, 1972, T AM MATH SOC, V171, P195