报告题目 (Title)：Approximation properties and ball-covering property of non-commutative spaces of operators
（非交换算子空间的逼近性质与球覆盖性质）
报告人 (Speaker)：刘锐 教授（南开大学）
报告时间 (Time)：2026年3月22日（周日）10:40
报告地点 (Place)：校本部GJ303
邀请人(Inviter)：李晋、席东盟、吴加勇
主办部门：理学院数学系
报告摘要：By dilation technique on Schauder frames, we extend Godefroy and Kalton's approximation theorem, and obtain that a separable Banach space has the unconditional bounded approximation property (UBAP) if and only if it can be embeded into a complemented subspace of a Banach space with unconditional finite-dimensional decomposition (UFDD). As applications on ball-covering property (BCP), we prove that if X^∗, Y are separable and (1) X or Y has the reverse metric approximation property (RMAP); or (2) X or Y has an approximating sequence, then the space of operators B(X,Y) has the uniform BCP. Furthermore, we point out the connections between the uniform BCP, u-ideals and the ball intersection property (BIP).
