English

Loose elements in binary and ternary matroids

Combinatorics 2025-01-15 v1

Abstract

We call a matroid element "loose" if it is contained in no circuits of size less than the rank of the matroid. A matroid in which all elements are loose is a paving matroid. Acketa determined all binary paving matroids, while Oxley specified all ternary paving matroids. We characterize the binary matroids that contain a loose element. For ternary matroids with a loose element, we show that their size is linear in terms of their rank. Moreover, for a prime power qq, we give a partial characterization of GF(q)GF(q)-representable matroids that have two or more loose elements; we note Rajpal's partial characterization of GF(q)GF(q)-representable paving matroids as a consequence.

Keywords

Cite

@article{arxiv.2501.07739,
  title  = {Loose elements in binary and ternary matroids},
  author = {Jagdeep Singh and Thomas Zaslavsky},
  journal= {arXiv preprint arXiv:2501.07739},
  year   = {2025}
}

Comments

13 pages

R2 v1 2026-06-28T21:05:19.881Z