English

$k$-loose elements and $k$-paving matroids

Combinatorics 2025-03-17 v3

Abstract

For a matroid of rank rr and a non-negative integer kk, an element is called kk-loose if every circuit containing it has size greater than rkr-k. Zaslavsky and the author characterized all binary matroids with a 11-loose element. In this paper, we establish a sharp linear bound on the size of a binary matroid, in terms of its rank, that contains a kk-loose element. A matroid is called kk-paving if all its elements are kk-loose. Rajpal showed that for a prime power qq, the rank of a GF(q)GF(q)-matroid that is kk-paving is bounded. We provide a bound on the rank of GF(q)GF(q)-matroids that are cosimple and have two kk-loose elements. Consequently, we deduce a bound on the rank of GF(q)GF(q)-matroids that are kk-paving. Additionally, we provide a bound on the size of binary matroids that are kk-paving.

Keywords

Cite

@article{arxiv.2412.10326,
  title  = {$k$-loose elements and $k$-paving matroids},
  author = {Jagdeep Singh},
  journal= {arXiv preprint arXiv:2412.10326},
  year   = {2025}
}

Comments

8 pages

R2 v1 2026-06-28T20:34:25.782Z