English

Partial flag incidence algebras

Combinatorics 2022-02-01 v2

Abstract

The nthn^{th} partial flag incidence algebra of a poset PP is the set of functions from PnP^n to some ring which are zero on non-partial flag vectors. These partial flag incidence algebras for n>2n>2 are not commutative, not unitary, and not associative. However, partial flag incidence algebras contain generalized zeta, delta, and M\"obius functions which are finer and more delicate invariants than their classical analogues. We also study some generalized characteristic polynomials of posets which are not evaluations of Tutte polynomials and compute them for Boolean lattices. Motivation for this work came from studying the matroid Kazhdan-Lusztig polynomials where partial flag Whitney numbers play a central role.

Keywords

Cite

@article{arxiv.1605.01685,
  title  = {Partial flag incidence algebras},
  author = {Max Wakefield},
  journal= {arXiv preprint arXiv:1605.01685},
  year   = {2022}
}

Comments

14 pages, revised version

R2 v1 2026-06-22T13:54:08.338Z