报告题目（中英文） (Title)：高Kazhdan投影和非局部化l2贝蒂数（Higher Kazhdan projections and delocalised ℓ2-Betti numbers）
报告人 (Speaker)：王航
报告时间（Time）：2023年9月14日（周四）14：00
报告地点 (Place)：校本部C110
邀请人(Inviter)：陈旦旦、孟沆洋
报告摘要：We explicitly describe the K-theory class of higher Kazhdan projections for certain free product groups and Cartesian products. Employing the explicit description, we obtain new calculations of Lott’s delocalised ℓ2-Betti numbers. In particular, we establish the first non-vanishing results for infinite groups.