Abstract
Let X be a K3 surface and L be an ample line bundle on it. In this article, we will give an alternative and elementary proof of Lelli-Chiesa’s theorem in the case of \(r= 2\). More precisely, we will prove that under certain conditions the second co-ordinate of the gonality sequence is constant along the smooth curves in the linear system |L|. Using Lelli-Chiesa’s theorem for \(r \ge 3\), we also extend Lelli-Chiesa’s theorem in the case of \(r= 2\) in weaker condition.
Similar content being viewed by others
References
Arbarello E, Cornalba M, Griffiths P A and Harris J, Geometry of Algebraic Curves. Vol. I, Grundlehren der Mathematischen Wissenschaften, Fundamental Principles of Mathematical Sciences, vol. 267 (1985) (New York: Springer-Verlag)
Ciliberto C and Pareschi G, Pencils of minimal degree on curves on a K3 surface, J. Reine Angew. Math. 460 (1995) 15–36
Donagi R and Morrison D R, Linear systems on K3-sections, J. Differential Geom. 29(1) (1989) 49–64
Eisenbud D, Lange H, Martens G and Schreyer F-O, The Clifford dimension of a projective curve, Compositio Math. 72(2) (1989) 173–204
Green M and Lazarsfeld R, Special divisors on curves on a K3 surface, Invent. Math. 89(2) (1987) 357–370
Lazarsfeld R, Brill–Noether–Petri without degenerations, J. Differential Geom. 23(3) (1986) 299–307
Lange H and Newstead P E, Clifford indices for vector bundles on curves, in: Affine Flag Manifolds and Principal Bundles (ed.) A Schmitt, Trends in Mathematics (2010) (Birkhäuser) pp. 165–202
Lelli-Chiesa M, Generalized Lazarsfeld–Mukai bundles and a conjecture of Donagi and Morrison, Adv. Math. 268 (2015) 529–563
Saint-Donat B, Projective models of K3 surfaces, Amer. J. Math. 96 (1974) 602–639
Tyurin A N, Cycles, curves and vector bundles on an algebraic surface, Duke Math. J. 54(1) (1987) 1–26
Acknowledgements
The author would like to thank Prof. A. J. Parameswaran for many useful discussions. He would also like to thank Prof. Ciliberto and Prof. P. Newstead for valuable comments and for pointing out the work done in this direction. He also thanks Krishanu Dan for a careful reading of the article.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicating Editor: D S Nagaraj
Rights and permissions
About this article
Cite this article
Pal, S. An elementary proof of Lelli-Chiesa’s theorem on constancy of second coordinate of gonality sequence. Proc Math Sci 132, 25 (2022). https://doi.org/10.1007/s12044-022-00677-4
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12044-022-00677-4