Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-26T10:00:47.935Z Has data issue: false hasContentIssue false

Examples of K-Unstable Fano Manifolds with the Picard Number 1

Published online by Cambridge University Press:  09 January 2017

Kento Fujita*
Affiliation:
Department of Mathematics, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan

Abstract

We show that the pair (X, –KX ) is K-unstable for a del Pezzo manifold X of degree 5 with dimension 4 or 5. This disproves a conjecture of Odaka and Okada.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 2017 

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. Berman, R., K-polystability of Q-Fano varieties admitting Kähler–Einstein metrics, Invent. Math. 203(3) (2015), 9731025.CrossRefGoogle Scholar
2. Birkar, C., Cascini, P., Hacon, C. D. and McKernan, J., Existence of minimal models for varieties of log general type, J. Am. Math. Soc. 23(2) (2010), 405468.Google Scholar
3. Chel'tsov, I. A. and Shramov, K. A., Extremal metrics on del Pezzo threefolds, Proc. Steklov Inst. Math. 264(1) (2009), 3044.Google Scholar
4. Chen, X. and Tian, G., Geometry of Kähler metrics and foliations by holomorphic discs, Publ. Math. IHES 107 (2008), 1107.CrossRefGoogle Scholar
5. Chen, X., Donaldson, S. and Sun, S., Kähler–Einstein metrics on Fano manifolds, I, Approximation of metrics with cone singularities, J. Am. Math. Soc. 28(1) (2015), 183197.Google Scholar
6. Chen, X., Donaldson, S. and Sun, S., Kähler–Einstein metrics on Fano manifolds, II, Limits with cone angle less than 2π , J. Am. Math. Soc. 28(1) (2015), 199234.Google Scholar
7. Chen, X., Donaldson, S. and Sun, S., Kähler–Einstein metrics on Fano manifolds, III, Limits as cone angle approaches 2π and completion of the main proof, J. Am. Math. Soc. 28(1) (2015), 235278.Google Scholar
8. Codogni, G., Fanelli, A., Svaldi, R. and Tasin, L., Fano varieties in Mori fibre spaces, Int. Math. Res. Not. 2016(7) (2016), 20262067.Google Scholar
9. Debarre, O., Iliev, A. and Manivel, L., On the period map for prime Fano threefolds of degree 10, J. Alg. Geom. 21(1) (2012), 2159.Google Scholar
10. Donaldson, S., Scalar curvature and stability of toric varieties, J. Diff. Geom. 62(2) (2002), 289349.Google Scholar
11. Donaldson, S., Lower bounds on the Calabi functional, J. Diff. Geom. 70(3) (2005), 453472.Google Scholar
12. Donaldson, S., A note an the α-invariant of the Mukai–Umemura 3-fold, Preprint (arXiv:0711.4357 [math.DG]; 2007).Google Scholar
13. Fujita, K., Optimal bounds for the volumes of Kähler-Einstein Fano manifolds, Am. J. Math., in press.Google Scholar
14. Fujita, K., On K-stability and the volume functions of ℚ-Fano varieties, Proc. Lond. Math. Soc. 113(5) (2016), 541582.Google Scholar
15. Fujita, T., On the structure of polarized manifolds with total deficiency one, II, J. Math. Soc. Jpn 32(3) (1981), 415434.Google Scholar
16. Fujita, T., Classification theories of polarized varieties, London Mathematical Society Lecture Note Series, Volume 155 (Cambridge University Press, 1990).Google Scholar
17. Iskovskih, V. A., Fano 3-folds I., Izv. Akad. Nauk SSSR Ser. Mat. 41(3) (1977), 516562.Google Scholar
18. Kaloghiros, A.-S., Küronya, A. and Lazić, V., Finite generation and geography of models, in Minimal models and extremal rays (Kyoto, 2011), Advanced Studies in Pure Mathematics, Volume 70, pp. 215246 (Mathematical Society of Japan, Tokyo, 2016).Google Scholar
19. Lazarsfeld, R., Positivity in algebraic geometry I, Classical setting: line bundles and linear series, Ergebnisse der Mathematik und ihrer Grenzgebiete, 3 Folge/A Series of Modern Surveys in Mathematics, Volume 48 (Springer, 2004).Google Scholar
20. Li, C., Wang, X. and Xu, C., Degeneration of Fano Kähler–Einstein manifolds, Preprint (arXiv:1411.0761v2 [math.AG]; 2014).Google Scholar
21. Mabuchi, T., K-stability of constant scalar curvature polarization, Preprint (arXiv:0812.4093 [math.DG]; 2008).Google Scholar
22. Mabuchi, T., A stronger concept of K-stability, Preprint (arXiv:0910.4617 [math.DG]; 2009).Google Scholar
23. Matsushima, Y., Sur la structure du groupe d’homéomorphismes analytiques d’une certaine variété Kählérienne, Nagoya Math. J. 11 (1957), 145150.Google Scholar
24. Odaka, Y., A generalization of the Ross–Thomas slope theory, Osaka J. Math. 50(1) (2013), 171185.Google Scholar
25. Odaka, Y., On parametrization, optimization and triviality of test configurations, Proc. Am. Math. Soc. 143(1) (2015), 2533.Google Scholar
26. Odaka, Y. and Okada, T., Birational superrigidity and slope stability of Fano manifolds, Math. Z. 275(3) (2013), 11091119.Google Scholar
27. Ross, J. and Thomas, R., A study of the Hilbert–Mumford criterion for the stability of projective varieties, J. Alg. Geom. 16(2) (2007), 201255.Google Scholar
28. Shokurov, V. V., 3-fold log models, J. Math. Sci. 81(3) (1996), 26672699.Google Scholar
29. Stoppa, J., K-stability of constant scalar curvature Kähler manifolds, Adv. Math. 221(4) (2009), 13971408.Google Scholar
30. Tian, G., On Calabi's conjecture for complex surfaces with positive first Chern class, Invent. Math. 101(1) (1990), 101172.Google Scholar
31. Tian, G., Kähler–Einstein metrics with positive scalar curvature, Invent. Math. 130(1) (1997), 137.Google Scholar
32. Tian, G., K-stability and Kähler–Einstein metrics, Commun. Pure Appl. Math. 68 (2015), 10851156.Google Scholar