Recurrence relations and asymptotics\\ for four-manifold invariants

The polynomial invariants qd 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 qd for large d. The relations are proved using moduli spaces of singular instantons.