English

Independent Hyperplanes in Oriented Paving Matroids

Combinatorics 2021-02-01 v1

Abstract

In 1993, Csima and Sawyer proved that in a non-pencil arrangement of n pseudolines, there are at least 613n\frac{6}{13}n simple points of intersection. Since pseudoline arrangements are the topological representations of reorientation classes of oriented matroids of rank 33, in this paper, we will use this result to prove by induction that an oriented paving matroid of rank r3r \ge 3 on nn elements, where n5+rn \geq 5+ r, has at least 1213(r1)(nr2)\frac{12}{13(r-1)} \binom{n}{r-2} independent hyperplanes, yielding a new necessary condition for a paving matroid to be orientable.

Keywords

Cite

@article{arxiv.2101.12290,
  title  = {Independent Hyperplanes in Oriented Paving Matroids},
  author = {Lamar Chidiac and Winfried Hochstättler},
  journal= {arXiv preprint arXiv:2101.12290},
  year   = {2021}
}
R2 v1 2026-06-23T22:38:20.377Z