Abstract
Let X be a smooth projective variety of dimension n, and let E be an ample vector bundle over X. We show that any Schur class of E, lying in the cohomology group of bidegree (n − 1, n − 1), has a representative which is strictly positive in the sense of smooth forms. This conforms the prediction of Griffiths conjecture on the positive polynomials of Chern classes/forms of an ample vector bundle on the form level, and thus strengthens the celebrated positivity results of Fulton and Lazarsfeld (1983) for certain degrees.
Similar content being viewed by others
References
Berndtsson B. Curvature of vector bundles associated to holomorphic fibrations. Ann of Math (2), 2009, 169: 531–560
Biswas I, Pingali V P. Metric properties of parabolic ample bundles. Int Math Res Not IMRN, 2020, 2020: 9336–9369
Bloch S, Gieseker D. The positivity of the Chern classes of an ample vector bundle. Invent Math, 1971, 12: 112–117
Boucksom S. Divisorial Zariski decompositions on compact complex manifolds. Ann Sci Éc Norm Super (4), 2004, 37: 45–76
Boucksom S, Demailly J-P, Păun M, et al. The pseudo-effective cone of a compact Kähler manifold and varieties of negative Kodaira dimension. J Algebraic Geom, 2013, 22: 201–248
Campana F, Flenner H. A characterization of ample vector bundles on a curve. Math Ann, 1990, 287: 571–575
Demailly J-P. Regularization of closed positive currents and intersection theory. J Algebraic Geom, 1992, 1: 361–409
Demailly J-P. Complex Analytic and Differential Geometry. Http://www-fourier.ujf-grenoble.fr/~demailly/manuscripts/agbook.pdf, 2012
Demailly J-P. Hermitian-Yang-Mills approach to the conjecture of Griffiths on the positivity of ample vector bundles. arXiv:2002.02677, 2020
Demailly J-P, Peternell T, Schneider M. Compact complex manifolds with numerically effective tangent bundles. J Algebraic Geom, 1994, 3: 295–345
Demailly J-P, Skoda H. Relations entre les notions de positivités de P. A. Griffiths et de S. Nakano pour les fibrés vectoriels. In: Séminaire Pierre Lelong-Henri Skoda (Analyse). Lecture Notes in Mathematics, vol. 822. Berlin-Heidelberg: Springer, 1980, 304–309
Diverio S. Segre forms and Kobayashi-Lübke inequality. Math Z, 2016, 283: 1033–1047
Fu J X, Xiao J. Relations between the Kähler cone and the balanced cone of a Kähler manifold. Adv Math, 2014, 263: 230–252
Fulton W. Ample vector bundles, Chern classes, and numerical criteria. Invent Math, 1976, 32: 171–178
Fulton W. Intersection Theory, 2nd ed. Results in Mathematics and Related Areas, 3rd Series. A Series of Modern Surveys in Mathematics, vol. 2. Berlin: Springer-Verlag, 1998
Fulton W, Lazarsfeld R. Positive polynomials for ample vector bundles. Ann of Math (2), 1983, 118: 35–60
Gieseker D. p-ample bundles and their Chern classes. Nagoya Math J, 1971, 43: 91–116
Griffiths P A. Hermitian differential geometry, Chern classes, and positive vector bundles. In: Global Analysis. Tokyo: University of Tokyo Press, 1969, 185–251
Guler D. Chern forms of positive vector bundles. PhD Thesis. Columbus: The Ohio State University, 2006
Guler D. On Segre forms of positive vector bundles. Canad Math Bull, 2012, 55: 108–113
Hartshorne R. Ample vector bundles. Publ Math Inst Hautes Études Sci, 1966, 29: 64–94
Kleiman S L. Ample vector bundles on algebraic surfaces. Proc Amer Math Soc, 1969, 21: 673–676
Lazarsfeld R. Positivity in Algebraic Geometry II. Positivity for Vector Bundles, and Multiplier Ideals. Results in Mathematics and Related Areas, 3rd Series. A Series of Modern Surveys in Mathematics, vol. 49. Berlin: SpringerVerlag, 2004
Li P. Nonnegative Hermitian vector bundles and Chern numbers. Math Ann, 2021, 380: 21–41
Liu K F, Sun X F, Yang X K. Positivity and vanishing theorems for ample vector bundles. J Algebraic Geom, 2013, 22: 303–331
Mourougane C, Takayama S. Hodge metrics and positivity of direct images. J Reine Angew Math, 2007, 606: 167–178
Nakayama N. Zariski-Decomposition and Abundance. MSJ Memoirs, vol. 14. Tokyo: Math Soc Japan, 2004
Naumann P. An approach to Griffiths conjecture. arXiv:1710.10034, 2017
Nyström D W. Duality between the pseudoeffective and the movable cone on a projective manifold. J Amer Math Soc, 2019, 32: 675–689
Pingali V P. Representability of Chern-Weil forms. Math Z, 2018, 288: 629–641
Ross J, Toma M. Hodge-Riemann bilinear relations for Schur classes of ample vector bundles. arXiv:1905.13636, 2019
Siu Y T. Analyticity of sets associated to Lelong numbers and the extension of closed positive currents. Invent Math, 1974, 27: 53–156
Toma M. A note on the cone of mobile curves. C R Acad Sci Ser I Math, 2010, 348: 71–73
Umemura H. Some results in the theory of vector bundles. Nagoya Math J, 1973, 52: 97–128
Usui S, Tango H. On numerical positivity of ample vector bundles with additional condition. J Math Kyoto Univ, 1977, 17: 151–164
Acknowledgements
This work was supported by Tsinghua University Initiative Scientific Research Program (Grant No. 2019Z07L02016) and National Natural Science Foundation of China (Grant No. 11901336). The author thanks Ping Li for his constructive comments, and thanks the referees for careful reading and helpful comments.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Xiao, J. On the positivity of high-degree Schur classes of an ample vector bundle. Sci. China Math. 65, 51–62 (2022). https://doi.org/10.1007/s11425-020-1868-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11425-020-1868-7