Abstract
We show that there exist Kähler–Einstein metrics on two exceptional Pasquier’s two-orbits varieties. As an application, we will provide a new example of K-unstable Fano manifold with Picard number one.
Similar content being viewed by others
References
Arzhantsev, I., Popovskiy, A.: Additive actions on projective hypersurfaces, Automorphisms in birational and affine geometry, Springer Proc. Math. Stat., vol. 79, Springer, Cham, pp. 17–33 (2014)
Berman, R.J.: K-polystability of \({{\mathbb{Q}}}\)-Fano varieties admitting Kähler-Einstein metrics. Invent. Math. 203(3), 973–1025 (2016)
Bai, C., Fu, B., Manivel, L.: On Fano complete intersections in rational homogeneous varieties. Math. Z. 295(1–2), 289–308 (2020)
Borel, A., Hirzebruch, F.: Characteristic classes and homogeneous spaces. II. Amer. J. Math. 81, 315–382 (1959)
Blum, H., Jonsson, M.: Thresholds, valuations, and K-stability. Adv. Math. 365, 107062, 57 (2020)
Bourbaki, Nicolas: Lie groups and Lie algebras. Chapters 4–6, Elements of Mathematics (Berlin), Springer-Verlag, Berlin, 2002, Translated from the 1968 French original by Andrew Pressley
Blum, H., Xu, C.: Uniqueness of K–polystable degenerations of Fano varieties. Ann. Math. 190(2), 609–656 (2019)
Chen, X., Donaldson, S., Sun, S.: Kähler-Einstein metrics on Fano manifolds. I: Approximation of metrics with cone singularities. J. Am. Math. Soc. 28(1), 183–197 (2015)
Chen, X., Donaldson, S., Sun, S.: Kähler-Einstein metrics on Fano manifolds. II: Limits with cone angle less than \(2\pi \). J. Am. Math. Soc. 28(1), 199–234 (2015)
Chen, X., Donaldson, S., Sun, S.: Kähler-Einstein metrics on Fano manifolds. III: Limits as cone angle approaches \(2\pi \) and completion of the main proof. J. Am. Math. Soc. 28(1), 235–278 (2015)
Delcroix, T.: K-stability of Fano spherical varieties. Ann. Sci. Éc. Norm. Supér. (4) 53(3), 615–662 (2020)
Delcroix, Thibaut: The Yau-Tian-Donaldson conjecture for cohomogeneity one manifolds, arXiv:2011.07135v1 (2020)
Donaldson, S.K.: Scalar curvature and stability of toric varieties. J. Differ. Geom. 62(2), 289–349 (2002)
Fu, B., Hwang, J.-M.: Special birational transformations of type (2,1). J. Algebraic Geom. 27(1), 55–89 (2018)
Fujita, K.: Towards a criterion for slope stability of Fano manifolds along divisors. Osaka J. Math. 52(1), 71–91 (2015)
Fujita, K.: Examples of K-unstable Fano manifolds with the Picard number 1. Proc. Edinb. Math. Soc. 60(4), 881–891 (2017)
Fujita, K.: A valuative criterion for uniform K-stability of \(\mathbb{Q}\)-Fano varieties. J. Reine Angew. Math. 751, 309–338 (2019)
Kanemitsu, A.: Fano manifolds and stability of tangent bundles. J. Reine Angew. Math. 774, 163–183 (2021)
Kuznetsov, A.G.: On linear sections of the spinor tenfold. I. Izv. Ross. Akad. Nauk Ser. Mat. 82(4), 53–114 (2018)
Li, C.: K-semistability is equivariant volume minimization. Duke Math. J. 166(16), 3147–3218 (2017)
Li, C.: \({\mathbb{G}}\)-uniform stability and Kähler-Einstein metrics on Fano varieties, arXiv:1907.09399v5 (2019)
Li, C., Wang, X., Xu, C.: Algebraicity of the metric tangent cones and equivariant K–stability, J. Amer. Math. Soc. 34(4), 1175–1214 (2021)
Li, C., Wang, X., Xu, C.: On the proper moduli spaces of smoothable Kähler–Einstein Fano varieties. Duke Math. J. 168(8), 1387–1459 (2019)
Matsushima, Y.: Sur la structure du groupe d’homéomorphismes analytiques d’une certaine variété kählérienne. Nagoya Math. J. 11, 145–150 (1957)
Odaka, Y.: A generalization of the Ross-Thomas slope theory. Osaka J. Math. 50(1), 171–185 (2013)
Odaka, Y.: Compact moduli spaces of Kähler-Einstein Fano varieties. Publ. Res. Inst. Math. Sci. 51(3), 549–565 (2015)
Odaka, Y., Okada, T.: Birational superrigidity and slope stability of Fano manifolds. Math. Z. 275(3–4), 1109–1119 (2013)
Pasquier, B.: On some smooth projective two-orbit varieties with Picard number 1. Math. Ann. 344(4), 963–987 (2009)
Ross, J., Thomas, R.: A study of the Hilbert-Mumford criterion for the stability of projective varieties. J. Algebraic Geom. 16(2), 201–255 (2007)
Spotti, C., Sun, S., Yao, C.: Existence and deformations of Kähler-Einstein metrics on smoothable \({\mathbb{Q}}\)-Fano varieties. Duke Math. J. 165(16), 3043–3083 (2016)
Tian, G.: Kähler-Einstein metrics with positive scalar curvature. Invent. Math. 130(1), 1–37 (1997)
Tian, G.: K-stability and Kähler-Einstein metrics. Commun. Pure Appl. Math. 68(7), 1085–1156 (2015)
Wang, X.: Height and GIT weight. Math. Res. Lett. 19(4), 909–926 (2012)
Zhuang, Z.: Optimal destabilizing centers and equivariant K-stability, arXiv:2004.09413v2 (2020)
Acknowledgements
The author wishes to express his gratitude to Professor Thibaut Delcroix for careful reading of the first draft of this paper, and also for discussions about the difference between his proof and our proof. The author is also grateful to Professors Kento Fujita and Yuji Odaka for helpful discussions and also for answering questions on K-stability of Fano varieties. The author also would like to thank Professor Baohua Fu for drawing his attention to [3] and for explaining Remark 5.3.
Funding
The author was a JSPS Research Fellow and supported by the Grant-in-Aid for JSPS fellows (JSPS KAKENHI Grant Number 18J00681).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The author states that there is no conflict of interest.
Data availability statement
Data sharing not applicable to this article as no datasets were generated or analysed during the current study.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Kanemitsu, A. Kähler–Einstein metrics on Pasquier’s two-orbits varieties. manuscripta math. 169, 297–311 (2022). https://doi.org/10.1007/s00229-021-01338-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00229-021-01338-y