Projective dimension and regularity of powers of edge ideals of vertex-weighted rooted forests

Abstract

In this paper we provide some exact formulas for projective dimension and the regularity of powers of edge ideals of vertex-weighted rooted forests. These formulas are functions of the weight of the vertices and the number of edges. We also give some examples to show that these formulas are related to direction selection and the assumptions about "rooted" forest such that $w(x)\ge 2$ if $d(x)\ne 1$ cannot be dropped.

arXiv admin note: text overlap with arXiv:1802.06316, arXiv:1904.02305