Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-26T16:40:06.939Z Has data issue: false hasContentIssue false

Variation of the Variety of Minimal Rational Tangents of Cyclic Coverings

Published online by Cambridge University Press:  28 August 2018

Hosung Kim*
Affiliation:
Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 02455, Republic of Korea (hosung@kias.re.kr)

Abstract

Let π: X → ℙn be the d-cyclic covering branched along a smooth hypersurface Y ⊂ ℙn of degree d, 3 ≤ dn. We identify the minimal rational curves on X with d-tangent lines of Y and describe the scheme structure of the variety of minimal rational tangents 𝒞x ⊂ ℙTx(X) at a general point xX. We also show that the projective isomorphism type of 𝒞x varies in a maximal way as x moves over general points of X.

MSC classification

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Bath, W., Peters, C. and Van de Ven, A., Compact complex surfaces. Ergebnisse der Mathematik und ihrer Grenzgebiete. (3) [Results in Mathematics and Related Areas. (3)], Volume 4. (Springer-Verlag, Berlin, 1984).Google Scholar
2.Hwang, J.-M., Geometry of minimal rational curves on Fano manifolds, In School on vanishing theorems and effective results in algebraic geometry (eds Demally, J.-P., Göttsche, L. G. and Lazarsfeld, R.), pp. 335393, ICTP Lecture Notes, Volume 6 (Abdus Salam International Centre for Theoretical Physics, Trieste, Italy, 2001).Google Scholar
3.Landsberg, J. M. and Robles, C., Lines and osculating lines of hypersurfaces, J. Lond. Math. Soc. 82(3) (2010), 733746.Google Scholar
4.Lazarsfeld, R., Positivity in algebraic geometry I (Springer, 2004).Google Scholar