Graph manifolds bounding rational homology balls

Nom de l'orateur
Lisa Lokteva
Etablissement de l'orateur
Glasgow University
Date et heure de l'exposé
Lieu de l'exposé
Salle des séminaires

The subject jokingly called "3.5-dimensional topology" concerns itself with the interactions between 3-manifolds and 4-manifolds, asking, given a 3-manifold, what 4-manifolds it is the boundary of. One big question in 3.5-dimensional topology is when a rational homology 3-sphere is the boundary of a rational homology 4-ball. (Guess what? Almost never.) We will discuss this question for a particular class of rational homology 3-spheres described by weighted graphs, presenting some results, conjectures, and ways forward.