Sharp proximity for group-labeled matroid bases

Let the elements of a matroid be labeled in an abelian group, and let \(F\) be a finite set of forbidden basis-label sums. We prove that, for every representable matroid, every basis is within \(|F|\) exchanges of an \(F\)-avoiding basis whenever one exists. This resolves the unweighted proximity conjecture for representable matroids over arbitrary fields, … Read more