From flops to diffeomorphism groups

Abstract

We exhibit many examples of closed complex surfaces whose diffeomorphism groups are not simply-connected and contain loops that are not homotopic to loops of symplectomorphisms.

major revision; accepted version

References in corpus (2)

• Positive scalar curvature, diffeomorphisms and the Seiberg-Witten invariants
• An obstruction to smooth isotopy in dimension 4