English

Finiteness theorems for matroid complexes with prescribed topology

Combinatorics 2020-09-29 v2

Abstract

It is known that there are finitely many simplicial complexes (up to isomorphism) with a given number of vertices. Translating to the language of hh-vectors, there are finitely many simplicial complexes of bounded dimension with h1=kh_1=k for any natural number kk. In this paper we study the question at the other end of the hh-vector: Are there only finitely many (d1)(d-1)-dimensional simplicial complexes with hd=kh_d=k for any given kk? The answer is no if we consider general complexes, but when focus on three cases coming from matroids: (i) independence complexes, (ii) broken circuit complexes, and (iii) order complexes of geometric lattices. We prove the answer is yes in cases (i) and (iii) and conjecture it is also true in case (ii).

Keywords

Cite

@article{arxiv.1809.00281,
  title  = {Finiteness theorems for matroid complexes with prescribed topology},
  author = {Federico Castillo and Jose Alejandro Samper},
  journal= {arXiv preprint arXiv:1809.00281},
  year   = {2020}
}

Comments

to appear in European Journal of Combinatorics

R2 v1 2026-06-23T03:51:50.404Z