English

Componentwise linearity of ideals arising from graphs

Commutative Algebra 2021-12-07 v1 Combinatorics

Abstract

Let GG be a simple undirected graph on nn vertices. Francisco and Van Tuyl have shown that if GG is chordal, then {xi,xj}EG<xi,xj>\bigcap_{\{x_i,x_j\}\in E_G} < x_i,x_j> is componentwise linear. A natural question that arises is for which tij>1t_{ij}>1 the ideal {xi,xj}EG<xi,xj>tij\bigcap_{\{x_i,x_j\}\in E_G}< x_i, x_j>^{t_{ij}} is componentwise linear, if GG is chordal. In this report we show that {xi,xj}EG<xi,xj>t\bigcap_{\{x_i,x_j\}\in E_G} < x_i, x_j>^{t} is componentwise linear for all n3n\geq 3 and positive tt, if GG is a complete graph. We give also an example where GG is chordal, but the intersection ideal is not componentwise linear for any t>1t>1.

Keywords

Cite

@article{arxiv.0911.2026,
  title  = {Componentwise linearity of ideals arising from graphs},
  author = {V. Crispin Quinonez and E. Emtander},
  journal= {arXiv preprint arXiv:0911.2026},
  year   = {2021}
}

Comments

5 pages

R2 v1 2026-06-21T14:09:59.522Z