Dima Panov (Kings College London) will speak in the geometry seminar on Tuesday 6th Feb. Dima’s title is *“Circle invariant symplectic hypersurfaces in dimension 6 and the Fano condition”* and his abstract is below. The talk will take place at 1.30pm in the Salle des Profs (9th floor of building NO).

This talk is based on a joint work with Nick Lindsay. A compact symplectic manifold (M,w) is called Fano if the classes c1(M) and [w] coincide in H^2(M). We prove that any symplectic Fano 6-manifold M with a Hamiltonian S1-action is simply connected and satisfies c1c2(M)=24. This is done by showing that the fixed submanifold of M on which the Hamiltonian attains its minimum is diffeomorphic to either a del Pezzo surface, a 2-sphere or a point.