Title
N-detachable pairs in 3-connected matroids II: Life in X
Abstract
Let M be a 3-connected matroid, and let N be a 3-connected minor of M. A pair {x1,x2}⊆E(M) is N-detachable if one of the matroids M/x1/x2 or M\x1\x2 is both 3-connected and has an N-minor. This is the second in a series of three papers where we describe the structures that arise when it is not possible to find an N-detachable pair in M. In the first paper in the series, we showed that, under mild assumptions, either M has an N-detachable pair, M has one of three particular 3-separators that can appear in a matroid with no N-detachable pairs, or there is a 3-separating set X with certain strong structural properties. In this paper, we analyse matroids with such a structured set X, and prove that they have either an N-detachable pair, or one of five particular 3-separators that can appear in a matroid with no N-detachable pairs.
Year
DOI
Venue
2021
10.1016/j.jctb.2020.07.008
Journal of Combinatorial Theory, Series B
Keywords
DocType
Volume
3-connected,Splitter theorem,Matroid structure
Journal
149
ISSN
Citations 
PageRank 
0095-8956
1
0.40
References 
Authors
0
3
Name
Order
Citations
PageRank
Nick Brettell110.73
Geoff Whittle247157.57
Alan Williams311.07