有理正规滚动割线簇的 Blow-up 代数
交换代数
2021-07-12 v1 代数几何
组合数学
摘要
本文主要关注平衡有理正规滚动的割线簇的 blow-up 代数。在第一部分,我们给出其相伴 Rees 代数与纤维锥的隐式定义方程。由此可判定纤维锥是 Cohen--Macaulay 正规整环。同时,这些纤维锥在特征零时具有有理奇点,在正特征时为 -有理。纤维锥的 Gorenstein 性质亦可被刻画。在第二部分,我们计算纤维锥的 Castelnuovo--Mumford 正则性与 -不变量。我们也给出了由割线簇所定义理想的约化数。
引用
@article{arxiv.2107.04168,
title = {Blow-up algebras of secant varieties of rational normal scrolls},
author = {Kuei-Nuan Lin and Yi-Huang Shen},
journal= {arXiv preprint arXiv:2107.04168},
year = {2021}
}
备注
Following the suggestion of experts, we split the original paper in arXiv:2009.03484v1 into two parts. And this will be the second part. The first part regarding the Cohen-Macaulayness of the fiber cone of the rational normal scroll will appear later as arXiv:2009.03484v2. Comments are welcome