Free arrangements and coefficients of characteristic polynomials
Combinatorics
2012-02-28 v3 Commutative Algebra
Abstract
Ziegler showed that free arrangements have free restricted multiarrangements (multirestrictions). After Ziegler's work, several results concerning "reverse direction", namely characterizing freeness of an arrangement via that of multirestriction, have appeared. In this paper, we prove that the second Betti number of the arrangement plays a crucial role.
Keywords
Cite
@article{arxiv.1109.0668,
title = {Free arrangements and coefficients of characteristic polynomials},
author = {Takuro Abe and Masahiko Yoshinaga},
journal= {arXiv preprint arXiv:1109.0668},
year = {2012}
}
Comments
13 pages, ver 2: minor modification