Recurrence relations and asymptotics for four-manifold invariants
  The polynomial invariants $q_d$ for a large class of smooth 4-manifolds are shown to satisfy universal relations. The relations reflect the possible genera of embedded surfaces in the 4-manifold and lead to a structure theorem for the polynomials. As an application, one can read off a lower bound for the genera of embedded surfaces from the asymptotics of $q_d$ for large $d$. The relations are proved using moduli spaces of singular instantons. 
Peter B. Kronheimer, Tomasz S. Mrowka