3-manifolds that bound no definite 4-manifold

Series
Geometry Topology Seminar
Time
Monday, April 19, 2021 - 2:00pm for 1 hour (actually 50 minutes)
Location
ONLINE
Speaker
Marco Golla – Université de Nantes – marco.golla@univ-nantes.fr – https://www.math.sciences.univ-nantes.fr/~golla/
Organizer
Siddhi Krishna

All 3-manifolds bound 4-manifolds, and many construction of 3-manifolds automatically come with a 4-manifold bounding it. Often times these 4-manifolds have definite intersection form. Using Heegaard Floer correction terms and an analysis of short characteristic covectors in bimodular lattices, we give an obstruction for a 3-manifold to bound a definite 4-manifold, and produce some concrete examples. This is joint work with Kyle Larson.