Bulletin of the Brazilian Mathematical Society, New Series ( IF 0.9 ) Pub Date : 2021-05-02 , DOI: 10.1007/s00574-021-00255-8 Fernando Abadie , Alcides Buss , Damián Ferraro
Building on previous papers by Anantharaman-Delaroche (AD) we introduce and study the notion of AD-amenability for partial actions and Fell bundles over discrete groups. We prove that the cross-sectional \(C^*\)-algebra of a Fell bundle is nuclear if and only if the underlying unit fibre is nuclear and the Fell bundle is AD-amenable. If a partial action is globalisable, then it is AD-amenable if and only if its globalisation is AD-amenable. Moreover, we prove that AD-amenability is preserved by (weak) equivalence of Fell bundles and, using a very recent idea of Ozawa and Suzuki, we show that AD-amenability is equivalent to an approximation property introduced by Exel.
中文翻译:
部分动作和跌落束的适应性和近似性质
在Anantharaman-Delaroche(AD)先前的论文的基础上,我们介绍并研究了离散组中部分动作和Fell束的AD适应性的概念。我们证明,当且仅当下面的单位纤维是核且Fell束可适应AD时,Fell束的横截面\(C ^ * \)-代数才是有核的。如果部分动作是可全局化的,则且仅当其全球化可用于AD时,它才可用于AD。而且,我们证明Fell束的(弱)等价关系保留了AD适应性,并且使用Ozawa和Suzuki的最新思想,我们证明了AD适应性等效于Exel引入的近似性质。