# Geometry and Topology Seminar

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.

In the fall of 2020, we will hold **online meetings** on
Zoom platform
(available every **Friday 1:00pm - 2:30pm**).

## Fall 2020

date | speaker | title | host(s) |
---|---|---|---|

Oct. 23 | Yu Li (Stony Brook) | On the ancient solutions to the Ricci flow | (Huang) |

Oct. 30 | Yi Lai (Berkeley) | A family of 3d steady gradient solitons that are flying wings | (Huang) |

Nov. 6 | Jiyuan Han (Purdue) | TBA | (Chen) |

Nov. 20 | Max Hallgren (Cornell) | TBA | (Huang) |

Dec. 4 | Yang Li (IAS) | TBA | (Chen) |

## Fall Abstracts

### Yu Li

Ancient solutions model the singularity formation of the Ricci flow. In two and three dimensions, we currently have complete classifications for κ-noncollapsed ancient solutions, while the higher dimensional problem remains open. This talk will survey some recent developments of κ-noncollapsed ancient solutions with nonnegative curvature in higher dimensions.

### Yi Lai

We found a family of $\mathbb{Z}_2\times O(2)$-symmetric 3d steady gradient Ricci solitons. We show that these solitons are all flying wings. This confirms a conjecture of Hamilton.

## Archive of past Geometry seminars

2019-2020 Geometry_and_Topology_Seminar_2019-2020

2018-2019 Geometry_and_Topology_Seminar_2018-2019

2017-2018 Geometry_and_Topology_Seminar_2017-2018

2016-2017 Geometry_and_Topology_Seminar_2016-2017

2015-2016: Geometry_and_Topology_Seminar_2015-2016

2014-2015: Geometry_and_Topology_Seminar_2014-2015

2013-2014: Geometry_and_Topology_Seminar_2013-2014

2012-2013: Geometry_and_Topology_Seminar_2012-2013

2011-2012: Geometry_and_Topology_Seminar_2011-2012

2010: Fall-2010-Geometry-Topology

Dynamics_Seminar_2020-2021