Ian Zemke (Princeton)

Title: Ribbon concordances and knot Floer homology

Abstract: A ribbon concordance is a concordance with only births and saddles. We will prove that the concordance map on knot Floer homology gives an obstruction to two knots being ribbon concordant. The proof involves a doubling trick, which shows that the induced concordance map is an injection. We will describe some generalizations and variations which are joint work (in several works) with Maggie Miller, Andras Juhasz and Adam Levine.