Brett Parker, UC Berkeley

TITLE: Orthogonally intersecting symplectic divisors

ABSTRACT: What arrangements of symplectic surfaces which intersect each other symplectically orthogonally can exist in a compact symplectic 4-manifold? I will show how to construct a "tropical" object from such an arrangement of symplectic surfaces and will use the properties of this "tropical" object to deduce the nonexistence of some arrangements of symplectic surfaces.