论文标题
表演组可正常时，无限制的花圈产品的度量近似
Metric approximations of unrestricted wreath products when the acting group is amenable
论文作者
论文摘要
我们给出一个简单而统一的证据，表明弱的sofic，sofic，linear sofic或超线性组的无限制花环产物分别是弱的，sofic，sofic，linear sofic或hyproylinear的。通过kaloujnine-krasner定理，这意味着具有正态商的组扩展可以保留上述四个度量近似属性。我们还讨论了共同群体的案例。
We give a simple and unified proof showing that the unrestricted wreath product of a weakly sofic, sofic, linear sofic, or hyperlinear group by an amenable group is weakly sofic, sofic, linear sofic, or hyperlinear, respectively. By means of the Kaloujnine-Krasner theorem, this implies that group extensions with amenable quotients preserve the four aforementioned metric approximation properties. We also discuss the case of co-amenable groups.
