2 citations · 3 across the 5 of their papers we have counts for
6 papers
The structure of delta-matroids with width one twists
Carolyn Chun, Rhiannon Hall, Criel Merino +2
The width of a delta-matroid is the difference in size between a maximal and minimal feasible set. We give a Rough Structure Theorem for delta-matroids that admit a twist of width…
On zeros of the characteristic polynomial of matroids of bounded tree-width
Carolyn Chun, Rhiannon Hall, Criel Merino +1
We develop some basic tools to work with representable matroids of bounded tree-width and use them to prove that, for any prime power and constant , the characteristic polyn…
On the relative importance of excluded minors
Rhiannon Hall, Dillon Mayhew, Stefan H. M. van Zwam
If EE is a set of matroids, then ex(EE) denotes the set of matroids that have no minor isomorphic to a member of EE. If EE' is a subset of EE, we say that EE' is /superfluous/ if e…
The excluded minors for near-regular matroids
Rhiannon Hall, Dillon Mayhew, Stefan H. M. van Zwam
In unpublished work, Geelen proved that a matroid is near-regular if and only if it has no minor isomorphic to: U2,5; U3,5; the Fano plane and its dual; the non-Fano and its dual;…
On contracting hyperplane elements from a 3-connected matroid
Rhiannon Hall
Let , , be the simple graph obtained from by adding three edges to a vertex part of size three. We prove that if is a hyperplane of a 3-conn…
Contracting an element from a cocircuit
Rhiannon Hall, Dillon Mayhew
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…