English

Two counterexamples for power ideals of arrangements

Combinatorics 2012-11-07 v1 Commutative Algebra

Abstract

We disprove Holtz and Ron's conjecture that the power ideal C_{A,-2} of a hyperplane arrangement A (also called the "internal zonotopal space") is generated by A-monomials. We also show that, in contrast with the case k \geq -2, the Hilbert series of C_{A,k} is not determined by the matroid of A for k \leq -6.

Keywords

Cite

@article{arxiv.1211.1368,
  title  = {Two counterexamples for power ideals of arrangements},
  author = {Federico Ardila and Alex Postnikov},
  journal= {arXiv preprint arXiv:1211.1368},
  year   = {2012}
}

Comments

This short note is a corrigendum to our paper "Combinatorics and geometry of power ideals"