English

Doubly exponentially many Ingleton matroids

Combinatorics 2017-10-06 v1

Abstract

A matroid is Ingleton if all quadruples of subsets of its ground set satisfy Ingleton's inequality. In particular, representable matroids are Ingleton. We show that the number of Ingleton matroids on ground set [n][n] is doubly exponential in nn; it follows that almost all Ingleton matroids are non-representable.

Keywords

Cite

@article{arxiv.1710.01924,
  title  = {Doubly exponentially many Ingleton matroids},
  author = {Peter Nelson and Jorn van der Pol},
  journal= {arXiv preprint arXiv:1710.01924},
  year   = {2017}
}

Comments

11 pages

R2 v1 2026-06-22T22:04:24.775Z