Very well-covered graphs and their h-vectors

Abstract

Let G be a Cohen–Macaulay very well-covered graph. We prove that the h-vector of the independence complex of G is precisely the f-vector of a flag complex. Moreover, we show that the h-vector of clique-whiskered graphs is exactly the h-vector of Cohen–Macaulay very well-covered graphs. In particular, we show that Kalai’s conjecture holds if G is a very well covered Cohen–Macaulay graph.