Title: Graphical arrangements and configuration spaces with obstacles

Abstract: 
Graphic subspace arrangements are associated to simple graphs. They generalize configuration spaces of points in Euclidean space, and have been studied in a few references. We use poset topology to compute the Poincare polynomials of the graph configuration spaces, or equivalently of the graphic arrangements. The answer is expressed in terms of acyclic orientations of the graph and of its bond poset. The stable homotopy type is deduced, and the result is expanded to treat more general families of configuration spaces of points in Euclidean space. This is joint work with Moez Bouzouita.