Speaker: Lowell Abrams, GWU
Date and time: Thursday, March 28, 4–5pm
Place: Rome 352
Abstract: A quadrangulated immersion of a graph G in a surface S is a drawing of G in S so that each crossing is transversal, each point of crossing is formed by exactly two edges, and each connected region of the complement of G in S is bounded by [portions of] four edges of G. We discuss basic constraints on quadrangulated immersions of cubic graphs in the sphere, and demonstrate various methods of constructing such immersions, including methods for constructing non-isomorphic immersions of the same graph. This is joint work with Yosef Berman, Michael Murphy, and Vance Faber.