Marco Golla (Uppsala) Correction terms and 4-ball genera of knots

Given a knot K in the 3-sphere, we use Heegaard Floer correction terms to give lower bounds on the first Betti number of (orientable and non-orientable) surfaces in the 4-ball with boundary K. An amusing feature of the non-orientable bound is its superadditivity with respect to connected sums. This is joint work with Marco Marengon. If time permits, I will discuss relations with deformations of singularities of curves (joint work with József Bodnár and Daniele Celoria).