2 papers
math.CO2025
Matroid lifts and representability
Daniel Irving Bernstein, Zach Walsh
A 1965 result of Crapo shows that every elementary lift of a matroid can be constructed from a linear class of circuits of . In a recent paper, Walsh generalized this constr…
math.CO2025
Excluding a line from -representable matroids
Jim Geelen, Peter Nelson, Zach Walsh
For each positive integer and each sufficiently large integer , we show that the maximum number of elements of a simple, rank-, -representable matroid with no…