Monday, August 26 at 2:00pm to 3:15pm
Kaprielian Hall (KAP), 245
3620 South Vermont Avenue, Los Angeles, CA 90089
Michael Willis, UCLA
ABSTRACT: I will discuss a method to define Khovanov and Lee homology for links L in connected sums of copies of S^1\times S^2. From here it is not hard to define an s-invariant s(L) that gives genus bounds on oriented cobordisms between links. I will discuss some applications to surfaces in certain 4-manifolds, including a proof that the s-invariant cannot detect exotic B^4's coming from Gluck twists of the standard B^4. If time allows, I will also discuss our new combinatorial proof of the slice Bennequin inequality in S^1\times S^2. All of this is joint work with Ciprian Manolescu, Marco Marengon, and Sucharit Sarkar.