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SUMMARY:Filtering the Heegaard Floer contact invariant - Gordana Matic (Un
 iversity of Georgia )
DTSTART:20170203T153000Z
DTEND:20170203T163000Z
UID:TALK70599@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:<span>Co-authors: Cagatay Kutluhan (&nbsp\;University at Buffa
 lo)\, Jeremy Van Horn-Morris (University of Arkansas)\, Andy Wand (Univers
 ity of Glasgow)<br></span><span><br>In this joint work with Kutluhan\, Van
  Horn-Morris and Wand\, we define the {\\it spectral order} invariant of c
 ontact structures in dimension three by refining the contact invariant fro
 m Heegaard Floer homology. This invariant takes values in the set&nbsp\;\\
 mathbb{Z}_{\\geq0}\\cup\\{\\infty\\}. It is zero for overtwisted contact s
 tructures\,&nbsp\;\\infty&nbsp\;for Stein fillable contact structures\, no
 n-decreasing under Legendrian surgery\, and computable from any supporting
  open book decomposition. It gives a criterion for tightness of a contact 
 structure stronger than that given by the Heegaard Floer contact invariant
 \, and an obstruction to existence of Stein cobordisms between contact 3-m
 anifolds. We show this by exhibiting an infinite family of examples with v
 anishing Heegaard Floer contact invariant on which our invariant assumes a
 n unbounded sequence of finite and non-zero values.</span>
LOCATION:Seminar Room 1\, Newton Institute
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