|Coordinates:||JH Michell Theatre in the Richard Berry Building|
|Speaker:||Shicheng Wang (Peking University)|
|Title:||Graph manifolds have virtually positive Seifert volume|
(Joint work with Pierre Derbez.)
The Seifert volume of each closed non-trivial graph manifold is virtually positive. Then for each closed orientable 3-manifold N, the set of mapping degrees D(M,N) is finite for any 3-manifold M, unless each prime factor of N is finitely covered by either a torus bundle, or a trivial circle bundle, or the 3-sphere.