Formal groups and quantum cohomology

Abstract

We use chain-level genus-zero Gromov–Witten theory to associate to any closed monotone symplectic manifold a formal group (loosely interpreted), whose Lie algebra is the odd-degree cohomology of the manifold (with vanishing bracket). When taken with coefficients in Fp for some prime p, the pth power map of the formal group is related to quantum Steenrod operations. The motivation for this construction comes from derived Picard groups of Fukaya categories, and from arithmetic aspects of mirror symmetry.