MIT Combinatorics Seminar Topology and combinatorics of boundary manifolds of arrangements Daniel Cohen  (Louisiana State University) http://www.math.lsu.edu/~cohen/ Friday, January 28, 2005    4:15 pm    Room 2-338 ABSTRACT In 1980, Orlik and Solomon proved that the cohomology ring of the complement of a complex hyperplane arrangement is determined by the intersection poset of the arrangement. The relationship between combinatorial and topological aspects of arrangements has subsequently become a focal point of the subject. In this talk, we investigate the extent to which the topology of the boundary manifold of an arrangement is combinatorially determined. Specifically, we discuss an analogue of the Orlik-Solomon theorem for the boundary manifold.