English

Contracting an element from a cocircuit

Combinatorics 2008-04-14 v2

Abstract

We consider the situation that M and N are 3-connected matroids such that |E(N)| > 3 and C* is a cocircuit of M with the property that M/y has an N-minor for some y in C*. We show that either there is an element x in C* such that si(M/x) or co(si(M/x)) is 3-connected with an N-minor, or there is a four-element fan of M that contains two elements of C* and an element x such that si(M/x) is 3-connected with an N-minor.

Cite

@article{arxiv.0801.2010,
  title  = {Contracting an element from a cocircuit},
  author = {Rhiannon Hall and Dillon Mayhew},
  journal= {arXiv preprint arXiv:0801.2010},
  year   = {2008}
}

Comments

23 pages, 1 figure. Minor changes to introduction

R2 v1 2026-06-21T10:02:32.730Z