The signature of cusped hyperbolic 4-manifolds (Stefano Riolo, Université de Genève)

28.09.2021 10:30

Closed oriented hyperbolic 4-manifolds have vanishing signature by the Hirzebruch signature theorem. What about non-compact manifolds of finite volume?

All previously known examples from the literature have zero signature, and some naïve considerations may give the feeling that this is true in general. Instead, we will see that every integer is the signature of a finite-volume hyperbolic 4-manifold, and, time permitting, some partial results on the geography of such manifolds.

Joint work with Sasha Kolpakov and Steve Tschantz.

Lieu

Bâtiment: Conseil Général 7-9

Room 1-05, Séminaire Groupes et Géométrie

entrée libre