Geometry and Topology Seminar 2019-2020
The Geometry and Topology seminar meets in room 901 of Van Vleck Hall on Fridays from 1:20pm - 2:10pm.
For more information, contact Shaosai Huang.
|Oct. 4||Ruobing Zhang (Stony Brook University)||Geometric analysis of collapsing Calabi-Yau spaces||(Chen)|
|Oct. 25||Emily Stark (Utah)||Action rigidity for free products of hyperbolic manifold groups||(Dymarz)|
|Nov. 8||Max Forester (University of Oklahoma)||TBA||(Dymarz)|
|Nov. 22||Yu Li (Stony Brook University)||On the structure of Ricci shrinkers||(Huang)|
This talk centers on the degenerations of Calabi-Yau metrics. We will focus on the interactions between algebraic degenerations and metric convergence with highly singular behaviors in the collapsing case. As the complex structures degenerate, the collapsing Calabi-Yau metrics may exhibit various wild geometric properties with highly non-algebraic features.
First, as motivating examples, we will describe our recent results on the new collapsing mechanisms of K3 surfaces. Next, we will switch to higher dimensions and we will exhibit some entirely new constructions of degenerating Calabi-Yau metrics which are expected to work in broader contexts. Complex structures degeneration will be accurately characterized by the bubbling and singularity analysis in a geometric manner.
We develop a structure theory for non-collapsed Ricci shrinkers without any curvature condition. As an application, we show that any Ricci shrinker whose second eigenvalue of the curvature operator is positive must be a quotient of sphere.
Archive of past Geometry seminars