2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78953The cobordism ring of symplectic manifolds defined by V.L. Ginzburg is shown to be isomorphic to the Pontrjagin ring of complex-oriented manifolds with free circle actions. This suggests an interpretation of the formal group law of complex cobordism, in terms of a composition-law on semiclassical expansions. An appendix discusses related questions about cobordism of toric varieties.A talk at the conference in honor of S.P. Novikov's 60th birthdaySymplectic GeometryAlgebraic TopologyQuantum Algebra81S10; 57R90, 14M25text