Geometry and Topology Seminar

In this talk, I will discuss a topological characterization of the

separability of surface subgroups in 3-manifold groups. The

characterization generalizes some earlier work of Rubinstein--Wang

using special cubulation techniques due to Daniel Wise. For surface

bundles whose monodromy has a nontrivial fractional Dehn twist

coefficient, we can construct essentially immersed but not

virtually embedded closed subsurfaces. This gives rise to new

examples of non-separable surface subgroups in many non-geometric

3-manifolds.