COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE I-MATHEMATIQUE
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1997年
/
324卷
/
11期
关键词:
D O I:
10.1016/S0764-4442(99)80409-1
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
We answer a question of R. Grigorchuk by showing the following characterization: for a countable group Gamma to be amenable, it is necessary and sufficient that any continuous action of Gamma on the Canter set has an invariant probability measure. The proof uses an easy variation of a classical result of Alexandroff and Urysohn: any metrisable Gamma-space is an equivariant subjective image of a Gamma-Cantor set.
机构:
St. Petersburg Department of the Steklov Mathematical Institute, St. PetersburgSt. Petersburg Department of the Steklov Mathematical Institute, St. Petersburg