# Filtering the Heegaard-Floer Contact Invariant

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Gordana Matic, University of Georgia
Fine Hall 314

This is a joint Symplectic Geometry - Topology seminar.   We define an invariant of contact structures in dimension three based on the contact invariant of Ozsvath and Szabo from Heegaard Floer homology. This invariant takes values in $\Z_{\geq0}\cup\{\infty\}$, is zero for overtwisted contact structures, $\infty$ for Stein fillable contact structures, and non-decreasing under Legendrian surgery. This is joint work with Cagaty Kutluhan, Jeremy Van Horn-Morris and Andy Wand.