Cobordism of Symplectic Manifolds and Asymptotic Expansions

The cobordism ring $\mathcal B_*$ of symplectic manifolds defined by V. L. Ginzburg is isomorphic to the Pontrjagin ring of complex-oriented manifolds with free circle actions. This provides an interpretation of the formal group law of complex cobordism as a composition-law on certain asymptotic expansions.