## 微分幾何・トポロジーセミナー

タイトル Quotients of étale groupoids and the abelianizations of groupoid C*-algebras 2019年4月23日 16:30～18:00 紅村 冬大 氏（慶應義塾大学） 矢上キャンパス14-733（14棟7階ミーティング3） The study of C*-algebras associated to étale groupoids, known to be groupoid C*-algebras, was initiated by Renault in 1980. It is a natural task to characterize the property of groupoid C*-algebras by the language of étale groupoids. In this talk, the speaker gives an overview of groupoid C*-algebras and quotient étale groupoids. Then, we apply quotients to analysis of the ideal structure and the abelianizations of groupoid C*-algebras. This talk is based on the preprint "Quotients of étale groupoids and the abelianizations of groupoid C*-algebras" (arXiv:1812.07194) by the speaker.