바로가기메뉴

본문 바로가기 주메뉴 바로가기

logo

  • P-ISSN1226-0657
  • E-ISSN2287-6081
  • KCI

A SYMBOLIC POWER OF THE IDEAL OF A STANDARD k-CONFIGURATION IN P2

Journal of the Korean Society of Mathematical Education Series B: The Pure and Applied Mathematics / Journal of the Korean Society of Mathematical Education Series B: The Pure and Applied Mathematics, (P)1226-0657; (E)2287-6081
2018, v.25 no.1, pp.31-38
https://doi.org/10.7468/jksmeb.2018.25.1.31
Shin, Yong-Su

Abstract

In [4], the authors show that if <TEX>${\mathbb{X}}$</TEX> is a <TEX>${\mathbb{k}}-configuration$</TEX> in <TEX>${\mathbb{P}}^2$</TEX> of type (<TEX>$d_1$</TEX>, <TEX>${\ldots}$</TEX>, <TEX>$d_s$</TEX>) with <TEX>$d_s$</TEX> > <TEX>$s{\geq}2$</TEX>, then <TEX>${\Delta}H_{m{\mathbb{X}}}(md_s-1)$</TEX> is the number of lines containing exactly <TEX>$d_s-points$</TEX> of <TEX>${\mathbb{X}}$</TEX> for <TEX>$m{\geq}2$</TEX>. They also show that if <TEX>${\mathbb{X}}$</TEX> is a <TEX>${\mathbb{k}}-configuration$</TEX> in <TEX>${\mathbb{P}}^2$</TEX> of type (1, 2, <TEX>${\ldots}$</TEX>, s) with <TEX>$s{\geq}2$</TEX>, then <TEX>${\Delta}H_{m{\mathbb{X}}}(m{\mathbb{X}}-1)$</TEX> is the number of lines containing exactly s-points in <TEX>${\mathbb{X}}$</TEX> for <TEX>$m{\geq}s+1$</TEX>. In this paper, we explore a standard <TEX>${\mathbb{k}}-configuration$</TEX> in <TEX>${\mathbb{P}}^2$</TEX> and find that if <TEX>${\mathbb{X}}$</TEX> is a standard <TEX>${\mathbb{k}}-configuration$</TEX> in <TEX>${\mathbb{P}}^2$</TEX> of type (1, 2, <TEX>${\ldots}$</TEX>, s) with <TEX>$s{\geq}2$</TEX>, then <TEX>${\Delta}H_{m{\mathbb{X}}}(m{\mathbb{X}}-1)=3$</TEX>, which is the number of lines containing exactly s-points in <TEX>${\mathbb{X}}$</TEX> for <TEX>$m{\geq}2$</TEX> instead of <TEX>$m{\geq}s+1$</TEX>.

keywords
symbolic powers, regular powers, points, star configurations

Journal of the Korean Society of Mathematical Education Series B: The Pure and Applied Mathematics