English

Complete intersections in certain affine and projective monomial curves

Commutative Algebra 2017-01-17 v1

Abstract

Let kk be an arbitrary field, the purpose of this work is to provide families of positive integers A={d1,,dn}\mathcal{A} = \{d_1,\ldots,d_n\} such that either the toric ideal IAI_{\mathcal A} of the affine monomial curve C={(td1,,tdn)  tk}Akn\mathcal C = \{(t^{d_1},\ldots,\,t^{d_n}) \ | \ t \in k\} \subset \mathbb{A}_k^n or the toric ideal IAI_{\mathcal A^{\star}} of its projective closure CPkn{\mathcal C^{\star}} \subset \mathbb{P}_k^n is a complete intersection. More precisely, we characterize the complete intersection property for IAI_{\mathcal A} and for IAI_{\mathcal A^{\star}} when: (a) A\mathcal{A} is a generalized arithmetic sequence, (b) A{dn}\mathcal{A} \setminus \{d_n\} is a generalized arithmetic sequence and dnZ+d_n \in \mathbb{Z}^+, (c) A\mathcal{A} consists of certain terms of the (p,q)(p,q)-Fibonacci sequence, and (d) A\mathcal{A} consists of certain terms of the (p,q)(p,q)-Lucas sequence. The results in this paper arise as consequences of those in Bermejo et al. [J. Symb. Comput. 42 (2007)], Bermejo and Garc\'{\i}a-Marco [J. Symb. Comput. (2014), to appear] and some new results regarding the toric ideal of the curve.

Keywords

Cite

@article{arxiv.1407.7007,
  title  = {Complete intersections in certain affine and projective monomial curves},
  author = {I. Bermejo and I. García-Marco},
  journal= {arXiv preprint arXiv:1407.7007},
  year   = {2017}
}

Comments

22 pages. To appear in Bulletin of the Brazilian Mathematical Society

R2 v1 2026-06-22T05:13:33.602Z