学术报告（戎小春 2026.6.15）

摘要：Fixing ϵ > 0, a complete Riemannian n-manifold M is called ϵ-collapsed, if every unit ball in M has a volume < ϵ. In Riemannian geometry, interplays between a collapsing geometry and topology has been an important component, and complexities in topology of a collapsed M is linked to a bound on curvature. Around 1980-2000, collapsed manifolds of bounded sectional curvature was intensively studied by Cheeger-Fukaya-Gromov and many others, which has found several applications.In this talk, we will survey progress in investigating a collapsed manifold M of Ricci Curvature/sectional curvature bounded from below and universal covering of every unit ball in M is not collapsed.