College of Liberal Arts & Sciences

# Topology Seminar

Speaker:

John Pardon (Princeton Unievrsity)

Topic:

Pontryagin-Thom for orbifold bordism

**Abstract: **

The classical Pontryaginâ€“Thom isomorphism equates manifold bordism groups with corresponding stable homotopy groups. This construction moreover generalizes to the equivariant context. I will discuss work which establishes a Pontryagin--Thom isomorphism for orbispaces (an orbispace is a "space" which is locally modelled on $Y/G$ for $Y$ a space and $G$ a finite group; examples of orbispaces include orbifolds and moduli spaces of pseudo-holomorphic curves). This involves defining a category of orbispectra and an involution of this category extending Spanier--Whitehead duality. Global homotopy theory also plays a key role.

Event Date:

October 1, 2020 - 2:30pm to 3:20pm

Location:

Online

Calendar Category:

Seminar

Seminar Category:

Geometry and Topology