Core Concepts
The Bhargava greedoid of a finite V-ultra triple is always a Gaussian elimination greedoid over any sufficiently large field.
Abstract
The paper introduces the notion of a V-ultra triple, which generalizes the concept of an ultra triple from previous work. It then shows that the Bhargava greedoid of a finite V-ultra triple is always a Gaussian elimination greedoid over any sufficiently large field.
Key highlights:
The Bhargava greedoid is a greedoid (a matroid-like set system) defined on a finite set E, based on a weight function w and a distance function d that satisfy certain axioms.
A Gaussian elimination greedoid is a greedoid analogue of a representable matroid, where the sets in the greedoid correspond to linearly independent sets of vectors.
The main result shows that the Bhargava greedoid of a finite V-ultra triple (E, w, d) is always a Gaussian elimination greedoid over any field K of size at least mcs(E, w, d), where mcs is the maximum size of a "clique" in the V-ultra triple.
When the weight function w is constant, the bound on the field size is also shown to be necessary.
The proof involves constructing a specific vector family over K whose Gaussian elimination greedoid matches the Bhargava greedoid of (E, w, d).