Joint IAS/Princeton University Symplectic Geometry Seminar

I will describe purely symplectic notions of normal crossings divisor and configuration. They are compatible with the existence of the desired auxiliary almost Kahler structures, provided ``existence" is suitably interpreted. These notions lead to a multifold version of Gompf's symplectic sum construction. They also imply that Brett Parker's work on exploded manifolds concerns a multifold version of the usual symplectic sum (or degeneration) formula for Gromov-Witten invariants. This talk will be about general symplectic topology, not GW-invariants. This is joint work with Mark McLean and Mohammad Tehrani.