English

Line Shellings of Geometric Lattices

Combinatorics 2026-01-09 v1

Abstract

Inspired by Bruggesser-Mani's line shellings of polytopes, we introduce line shellings for the lattice of flats of a matroid: given a normal complex for a Bergman fan of a matroid induced by a building set, we show that the lexicographic order of the coordinates of its vertices is a shelling order. This gives a new proof of Bj\"orner's classical result that the order complex of the lattice of flats of a matroid is shellable, and demonstrates shellability for all nested set complexes for matroids.

Keywords

Cite

@article{arxiv.2601.05119,
  title  = {Line Shellings of Geometric Lattices},
  author = {Spencer Backman and Galen Dorpalen-Barry and Anastasia Nathanson and Ethan Partida and Noah Prime},
  journal= {arXiv preprint arXiv:2601.05119},
  year   = {2026}
}

Comments

33 pages. Comments welcome!