English

Fiber cones of rational normal scrolls are Cohen-Macaulay

Commutative Algebra 2021-07-13 v2 Algebraic Geometry

Abstract

In this short paper, we show that the fiber cones of rational normal scrolls are Cohen-Macaulay. As an application, we compute their Castelnuovo-Mumford regularities and a\mathbf{a}-invariants, as well as the reduction number of the defining ideals of the rational normal scrolls. We also characterize the Gorensteinness of the fiber cone.

Keywords

Cite

@article{arxiv.2009.03484,
  title  = {Fiber cones of rational normal scrolls are Cohen-Macaulay},
  author = {Kuei-Nuan Lin and Yi-Huang Shen},
  journal= {arXiv preprint arXiv:2009.03484},
  year   = {2021}
}

Comments

Following the suggestion of experts, we split the original paper in arXiv:2009.03484v1 into two parts. And this is the first part, showing up as arXiv:2009.03484v2, with title changed. The second part regarding the regularity of the secant variety appears as arXiv:2107.04168. A result regarding Gorensteinness is new. Comments are welcome!

R2 v1 2026-06-23T18:22:47.599Z