Generalized 1-skeleta and a lifting result

Abstract

In their paper "1-skeleta, Betti numbers, and equivariant cohomology" Guillemin and Zara described some beautiful constructions enabling them to use Morse theory on a certain class 1-skeleta including 1-skeleta of simple polytopes. In this paper we extend some of the notions and constructions from that paper to a larger class of 1-skeleta that includes 1-skeleta of projected simple polytopes. As an application of these ideas we prove a lifting result for 1-skeleta, which yields a characterization of 1-skeleta coming from projected simple polytopes.