Total cut complexes and their duals

Abstract

We study the total $d$-cut complexes and their Alexander duals. We give some results about the connectivity in general and in terms of the grith of the graph. For $d\ge 3$, the homotopy type of these complexes is calculated for: $p$th power of a cycle with at least $(2r)d$ vertices where $p\le r$; the $r$th power of a cycle with at least $2rd-(r-1)$ vertices where $r\ge 3$; and the $2$th power of a cycle with at least $3d$ vertices. These calculations solve a conjecture of Bayer, Denker, Milutinović, Rowlands, Sundaram and Xue. The homotopy type of the $2$-total cut complex for any $r$th power of a cycle with $r\ge 3$ also is calculated, solving a conjecture of Chauhan, Shukla and Vinayak. We also study the complexes of cartesian products of paths and of cartesian products of complete graphs for the total $2$-cut complex.