English

Non-normal edge rings satisfying $(S_2)$-condition

Commutative Algebra 2023-10-13 v4 Combinatorics

Abstract

Let GG be a finite simple connected graph on the vertex set V(G)=[d]={1,,d}V(G)=[d]=\{1,\dots ,d\}, with edge set E(G)={e1,,en}E(G)=\{e_{1},\dots , e_{n}\}. Let K[t]=K[t1,,td]K[\mathbf{t}]=K[t_{1},\dots , t_{d}] be the polynomial ring in dd variables over a field KK. The edge ring of GG is the semigroup ring K[G]K[G] generated by monomials te:=titj\mathbf{t}^{e}:=t_{i}t_{j}, for e={i,j}E(G)e=\{i,j\} \in E(G). In this paper, we will prove that, given integers dd and nn, where d7d\geq 7 and d+1nd27d+242d+1\leq n\leq \frac{d^{2}-7d+24}{2}, there exists a finite simple connected graph GG with V(G)=d|V(G)|=d and E(G)=n|E(G)|=n, such that K[G]K[G] is non-normal and satisfies (S2)(S_{2})-condition.

Keywords

Cite

@article{arxiv.2207.01217,
  title  = {Non-normal edge rings satisfying $(S_2)$-condition},
  author = {Nayana Shibu Deepthi},
  journal= {arXiv preprint arXiv:2207.01217},
  year   = {2023}
}
R2 v1 2026-06-24T12:12:49.354Z