English

High order free hyperplane arrangements in 3-dimensional vector spaces

Combinatorics 2021-09-20 v3

Abstract

Holm introduced mm-free \ell-arrangements which is a generalization of free arrangements, while he asked whether all \ell-arrangements are mm-free for mm large enough. Recently Abe and the author verified that this question is in the negative when 4\ell\geq 4. In this paper we verify that 33-arrangements A\mathscr{A} are mm-free and compute the mm-exponents for all mA+2m\geq |\mathscr{A}|+2, where A|\mathscr{A}| is the cardinality of A\mathscr{A}. Hence Holm's question is in the positive when =3\ell=3. Finally we prove that 33-dimensional Weyl arrangements of types A and B are mm-free for all m0m\geq 0.

Cite

@article{arxiv.1903.03249,
  title  = {High order free hyperplane arrangements in 3-dimensional vector spaces},
  author = {Norihiro Nakashima},
  journal= {arXiv preprint arXiv:1903.03249},
  year   = {2021}
}

Comments

25 pages, 3 figures

R2 v1 2026-06-23T08:01:52.469Z