5 papers
Connection Matrices in Macaulay2
Paul Görlach, Joris Koefler, Anna-Laura Sattelberger +4
In this article, we describe the theoretical foundations of the Macaulay2 package ConnectionMatrices and explain how to use it. For a left ideal in the Weyl algebra that is of fini…
The Self-Projecting Grassmannian
Alheydis Geiger, Francesca Zaffalon
We introduce the self-projecting Grassmannian, an irreducible subvariety of the Grassmannian parametrizing linear subspaces that satisfy a generalized self-duality condition. We st…
Computing positroid cells in the Grassmannian of lines, their boundaries and their intersections
Susama Agarwala, Fatemeh Mohammadi, Francesca Zaffalon
Positroids are families of matroids introduced by Postnikov in the study of non-negative Grassmannians. In particular, positroids enumerate a CW decomposition of the totally non-ne…
How to stab a polytope
Sebastian Seemann, Francesca Zaffalon
We study the set of linear subspaces of a fixed dimension intersecting a given polytope. To describe this set as a semialgebraic subset of a Grassmannian, we introduce a Schubert a…
Combinatorics of Essential Sets for Positroids
Fatemeh Mohammadi, Francesca Zaffalon
Positroids are a family of matroids introduced by Postnikov in the study of non-negative Grassmannians. Postnikov identified several combinatorial objects in bijections with positr…