# On normal crossings symplectic divisors

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Aleksey Zinger , Stony Brook
Fine Hall 322

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.