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Acta Mathematica Vietnamica

Non-normal Edge Rings Satisfying (S2)-condition

icon-email Nayana Shibu Deepthi

Abstract

Let G be a finite simple connected graph on the vertex set V(G)=[d]={1,,d} with edge set E(G)={e1,,en}. Let K[t]=K[t1,,td] be the polynomial ring in d variables over a field K. The edge ring of G is the affine semigroup ring K[G] generated by monomials te:=titj, for e={i,j}E(G). In this paper, we will prove that, given integers d and n, where d7 and d+1nd27d+242, there exists a finite simple connected graph G with |V(G)|=d and |E(G)|=n, such that K[G] is non-normal and satisfies (S2)-condition.