Twisted substitutions and fundamental groups of Lefschetz fibraitons

Naoyuki Monden

Every finitely presented group can be realized as the fundamental group of the total space of a Lefschetz fibration over the 2-sphere admitting a (-1)-section. This follows from the works of Gompf and Donaldson. In this talk, we give the explicit monodromy of a Lefschetz fibration admitting a (-1)-section whose fundamental group is a given finitely presented group using "twisted substitution" techniques. This is the joint work with Ryoma Kobayashi in Tokyo University of Science. (1 hour long talk)

http://scgp.stonybrook.edu/video_portal/video.php?id=1332

Simons- Workshop on Topology and Invariants of 4-Manifolds