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 , we give a partial characterization of -representable matroids that have two or more loose elements; we note Rajpal's partial characterization of -representable paving matroids as a consequence.
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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}
}
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13 pages