New examples of Weierstrass semigroups associated with a double covering of a curve on a Hirzebruch surface of degree one

被引:0
作者
Kenta Watanabe
机构
[1] Nihon University,College of Science and Technology
来源
Beiträge zur Algebra und Geometrie / Contributions to Algebra and Geometry | 2023年 / 64卷
关键词
Weierstrass semigroup; Double covering of a curve; Hirzebruch surface; Normalization of a curve; 14J26; 14H51; 14H55;
D O I
暂无
中图分类号
学科分类号
摘要
Let φ:Σ1⟶P2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi :\Sigma _1\longrightarrow {\mathbb {P}}^2$$\end{document} be a blow up at a point on P2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb {P}}^2$$\end{document}. Let C be the proper transform of a smooth plane curve of degree d≥4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d\ge 4$$\end{document} by φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi $$\end{document}, and let P be a point on C. Let π:C~⟶C\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pi :{\tilde{C}}\longrightarrow C$$\end{document} be a double covering branched along the reduced divisor on C obtained as the intersection of C and a reduced divisor in |-2KΣ1|\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$|-2K_{\Sigma _1}|$$\end{document} containing P. In this paper, we investigate the Weierstrass semigroup H(P~)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$H({\tilde{P}})$$\end{document} at the ramification point P~\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\tilde{P}}$$\end{document} of π\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pi $$\end{document} over P, in the case where the intersection multiplicity at φ(P)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi (P)$$\end{document} of φ(C)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi (C)$$\end{document} and the tangent line at φ(P)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi (P)$$\end{document} of φ(C)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi (C)$$\end{document} is d-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d-1$$\end{document}.
引用
收藏
页码:145 / 153
页数:8
相关论文
共 8 条
  • [1] Kang E(2007)A Weierstrass semigroup at a pair of inflection points on a smooth plane curve Bull. Korean Math. Soc. 44 369-378
  • [2] Kim SJ(2011)On Weierstrass semigroups of double coverings of genus three curves Semigroup Forum 83 479-488
  • [3] Komeda J(1994)Weierstrass points and double coverings of curves with application: symmetric numerical semigroups which cannot be realized as Weierstrass semigroups Manuscr. Math. 83 39-58
  • [4] Torres F(2013)An example of the Weierstrass semigroup of a pointed curve on K3 surfaces Semigroup Forum 86 395-403
  • [5] Watanabe K(2019)A double covering of curves on a Hirzebruch surface of degree one and Weierstrass semigroups Semigroup Forum 98 422-429
  • [6] Watanabe K(2015)On extensions of a double covering of plane curves and Weierstrass semigroups of the double covering type Semigroup Forum 91 517-523
  • [7] Watanabe K(undefined)undefined undefined undefined undefined-undefined
  • [8] Komeda J(undefined)undefined undefined undefined undefined-undefined