Correction terms in Heegaard Floer homology and the non-orientable slice genus.
Marco Marengon (Imperial)
Monday 24th October, 2016 16:00-17:00 Maths 522
Given a knot K in the 3-sphere S^3, its non-orientable slice genus is the minimum first Betti number of a non-orientable surface S, properly embedded in D^4, such that the boundary of S is K. Using correction terms in Heegaard Floer homology, we will find a lower bound to the non-orientable slice genus of K, which turns out to be a concordance invariant. We will then compare it to previous lower bounds, and discuss some of its interesting properties, such as superadditivity, which implies that the bound for K#K can sometimes be better than the bound for K.