Academics

YMSC Topology Seminar | Exotic boundary Dehn twist on 4-manifolds

Time:Mon.,4:00-5:00 pm, Mar. 18, 2024

Venue:C654, Shuangqing Complex Building A 清华大学双清综合楼A座 C654 Online: Zoom meeting ID: 405 416 0815 Password: 111111

Organizer:陈伟彦、高鸿灏、黄意、林剑锋

Speaker:Jianfeng LIN 林剑锋 (YMSC)

Abstract:

Given a 4-manifold X bounded by a Seifert manifold, one can use the circle action on the boundary to define a diffeomorphism on X, called the boundary Dehn twist. Such boundary Dehn twist naturally arises from singularity theory. A recent result by Konno-Mallick-Taniguchi shows that when X is a certain Milnor fiber, this boundary Dehn twist is topologically isotopic to the identity but not smoothly so. In this talk, we will discuss an approach to generalize this result using monopole Floer homology. Motivation from algebraic geometry will also be discussed. This talk is based on a joint work in progress with Hokuto Konno, Anubhav Mukherjee and Juan Munoz-Echaniz.

DATEMarch 18, 2024
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