English

Permutohedron's volume via Dyck paths

Combinatorics 2025-04-01 v1

Abstract

In a recent project, Castillo, Libedinsky, Plaza, and the author established a deep connection between the size of lower Bruhat intervals in affine Weyl groups and the volume of the permutohedron, showing that the former can be expressed as a linear combination of the latter. In this paper, we provide a formula for the volume of this polytope in terms of Dyck paths. Thus, we present a shorter, alternative, and enlightening proof of a previous formula given by Postnikov.

Keywords

Cite

@article{arxiv.2503.23122,
  title  = {Permutohedron's volume via Dyck paths},
  author = {Damian de la Fuente},
  journal= {arXiv preprint arXiv:2503.23122},
  year   = {2025}
}

Comments

11 pages

R2 v1 2026-06-28T22:39:03.102Z