### 3-manifolds that bound no definite 4-manifold

- Series
- Geometry Topology Seminar
- Time
- Monday, April 19, 2021 - 14:00 for 1 hour (actually 50 minutes)
- Location
- ONLINE
- Speaker
- Marco Golla – Université de Nantes – marco.golla@univ-nantes.fr

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.