5 papers
The critical number of -free triangle-free binary matroids
Peter Nelson, Kazuhiro Nomoto
A simple binary matroid, viewed as a restriction of a finite binary projective geometry , is -free if for any rank- flat of , its intersection wit…
The smallest -free and triangle-free binary matroids
Peter Nelson, Kazuhiro Nomoto
We determine the smallest simple triangle-free binary matroids that have no five-element independent flat. This solves a special case of a conjecture of Nelson and Norin.
The structure of -free and triangle-free binary matroids
Peter Nelson, Kazuhiro Nomoto
A simple binary matroid is called -free if none of its rank-4 flats are independent sets. These objects can be equivalently defined as the sets of points in fo…
The structure of claw-free binary matroids
Peter Nelson, Kazuhiro Nomoto
A simple binary matroid is called claw-free if none of its rank-3 flats are independent sets. These objects can be equivalently defined as the sets of points in $\mathrm{PG}(n-…
Stability and exact Turan numbers for matroids
Hong Liu, Sammy Luo, Peter Nelson +1
We consider the Turán-type problem of bounding the size of a set that does not contain a linear copy of a given fixed set ,…