English

Connectivity through bounds for the Castelnuovo-Mumford regularity

Combinatorics 2016-12-08 v3 Commutative Algebra

Abstract

We present a simple method to obtain information regarding the connectivity of the 1-skeleta of a wide family of simplicial complexes through bounds for the Castelnuovo-Mumford regularity of their Stanley-Reisner rings. In this way we generalize and unify two results on connectivity: one by Balinsky and Barnette, one by Athanasiadis. In particular, if Δ\Delta is a simplicial dd-pseudomanifold, and ss is the highest integer such that there is an ss-dimensional simplex not contained in Δ\Delta, but such that its boundary is, then the 1-skeleton of Δ\Delta is (s+1)ds\left\lceil \frac{(s+1)d}{s} \right\rceil-connected. We also show that this bound on the connectivity is tight.

Keywords

Cite

@article{arxiv.1412.5920,
  title  = {Connectivity through bounds for the Castelnuovo-Mumford regularity},
  author = {Gabriele Balletti},
  journal= {arXiv preprint arXiv:1412.5920},
  year   = {2016}
}

Comments

6 pages. Final version