English

Construction of the moduli space of reduced Groebner bases

Algebraic Geometry 2020-07-28 v4 Commutative Algebra

Abstract

For a given monomial ideal Jk[x1,,xn]J \subset k[x_1, \ldots, x_n] and a given monomial order \prec, the moduli functor of all reduced Gr\"obner bases with respect to \prec whose initial ideal is JJ is determined. In some cases, such a functor is representable by an affine scheme of finite type over kk, and a locally closed subfunctor of a Hilbert scheme. The moduli space is called the Gr\"obner basis scheme, the Gr\"obner strata and so on if it exists. This paper introduces an alternative procedure for explicitly constructing a defining ideal of the Gr\"obner basis scheme and its Zariski tangent spaces by studying combinatorics on the standard set associated to JJ. That is a generalization of Robbiano and Lederer's technique. We also see that we can make an implementation of that. Moreover, as a generalization of Robbiano's result, we show that if the Gr\"obner basis scheme for \prec and JJ defined over the rational numbers Q\mathbb{Q} is nonsingular at the Q\mathbb{Q}-rational point corresponding to JJ, then the Gr\"obner basis scheme for \prec and JJ defined over any commutative ring kk is isomorphic to an affine space over kk.

Keywords

Cite

@article{arxiv.1707.06448,
  title  = {Construction of the moduli space of reduced Groebner bases},
  author = {Yuta Kambe},
  journal= {arXiv preprint arXiv:1707.06448},
  year   = {2020}
}

Comments

Withdraw. There is no new method and new contribution. Please see "Gr\"obner strata in the {H}ilbert scheme of points", Mathias Lederer, J. Commut. Algebra, Volume 3, Number 3 (2011), 349-404