papers

Publications (73)

math.CO2014

The densest matroids in minor-closed classes with exponential growth rate

Jim Geelen, Peter Nelson

The for a nonempty minor-closed class of matroids is the function whose value at an integer is define…

math.CO2021

Enumeration of extensions of the cycle matroid of a complete graph

Peter Nelson, Shayla Redlin, Jorn van der Pol

We prove that the number of single element extensions of is . This is done using a characterization of extensions as "linear subclasses".

math.CO2025

Composition Direction of Seymour's Theorem for Regular Matroids -- Formally Verified

Martin Dvorak, Tristan Figueroa-Reid, Rida Hamadani +8

Seymour's decomposition theorem is a hallmark result in matroid theory presenting a structural characterization of the class of regular matroids. Formalization of matroid theory fa…

math.CO2012

A Density Hales-Jewett Theorem for matroids

Jim Geelen, Peter Nelson

We show that, if is a real number, and are integers, and is a prime power, then every simple matroid of sufficiently large rank, with no $U_{…

math.CO2018

Matroids with no -minor and many hyperplanes

Adam Brown, Peter Nelson

We construct, for every and every prime power , a rank- matroid with no -minor, having more hyperplanes than the rank- projective geometry over $…

math.CO2012

An analogue of the Erdős-Stone theorem for finite geometries

Jim Geelen, Peter Nelson

For a set of points in $\PG(m-1,q)$, let $\ex_q(G;n)$, denote the maximum size of a collection of points in $\PG(n-1,q)$ not containing a copy of , up to projective equivale…