Subsurface projections of mapping class groups

Geometry & Topology
Event time: 
Thursday, January 24, 2008 - 11:30am to Wednesday, January 23, 2008 - 7:00pm
431 DL
Yair Minsky
Speaker affiliation: 
Event description: 

There is a useful family of projections
$ MCG(S) \to C(W) $
from the mapping class group of a surface S to curve complexes of subsurfaces W. Together they give a map to the product of curve complexes,
MCG(S) \to \prod_W C(W).

I will discuss a characterization of the image of this map in terms of simple inequalities. This characterization makes some simple “convex hull” constructions possible in MCG(S), and has applications to rigidity properties of the group. Joint work with J. Behrstock, B. Kleiner, and L. Mosher.