论文标题
内部木素的成本
Cost of inner amenable groupoids
论文作者
论文摘要
Kida和Tucker-Drob最近将可数组的内部不合适性概念扩展到了离散的P.M.P.群体素。 In this article, we show that inner amenable groupoids have "fixed priced 1" in the sense that every principal extension of an inner amenable groupoid has cost 1. This simultaneously generalizes and unifies two well known results on cost from the literature, namely, (1) a theorem of Kechris stating that every ergodic p.m.p.在其完整组中承认非平凡的渐近中心序列的等价关系成本为1，（2）Tucker-Drob的定理指出，内部可及的组具有固定价格1。
Kida and Tucker-Drob recently extended the notion of inner amenability from countable groups to discrete p.m.p. groupoids. In this article, we show that inner amenable groupoids have "fixed priced 1" in the sense that every principal extension of an inner amenable groupoid has cost 1. This simultaneously generalizes and unifies two well known results on cost from the literature, namely, (1) a theorem of Kechris stating that every ergodic p.m.p. equivalence relation admitting a nontrivial asymptotically central sequence in its full group has cost 1, and (2) a theorem of Tucker-Drob stating that inner amenable groups have fixed price 1.
