English

A Combinatorial Formula for Kazhdan-Lusztig Polynomials of Sparse Paving Matroids

Combinatorics 2020-06-19 v1

Abstract

We prove the positivity of Kazhdan-Lusztig polynomials for sparse paving matroids, which are known to be logarithmically almost all matroids, but are conjectured to be almost all matroids. The positivity follows from a remarkably simple combinatorial formula we discovered for these polynomials using skew young tableaux. This supports the conjecture that Kazhdan-Lusztig polynomials for all matroids have non-negative coeffiecients. In special cases, such as uniform matroids, our formula has a nice combinatorial interpretation.

Keywords

Cite

@article{arxiv.2006.10209,
  title  = {A Combinatorial Formula for Kazhdan-Lusztig Polynomials of Sparse Paving Matroids},
  author = {Kyungyong Lee and George D. Nasr and Jamie Radcliffe},
  journal= {arXiv preprint arXiv:2006.10209},
  year   = {2020}
}