Abstract
The Donaldson–Fujiki Kähler reduction of the space of compatible almost complex structures, leading to the interpretation of the scalar curvature of Kähler metrics as a moment map, can be lifted canonically to a hyperkähler reduction. Donaldson proposed to consider the corresponding vanishing moment map conditions as (fully nonlinear) analogues of Hitchin’s equations, for which the underlying bundle is replaced by a polarised manifold. However this construction is well understood only in the case of complex curves. In this paper we study Donaldson’s hyperkähler reduction on abelian varieties and toric manifolds. We obtain a decoupling result, a variational characterisation, a relation to K-stability in the toric case, and prove existence and uniqueness under suitable assumptions on the “Higgs tensor”. We also discuss some aspects of the analogy with Higgs bundles.
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Notes
Notice that there is a sign misprint in the statement; the correct sign can be found in [16, equation (3.3.6)].
References
Abreu, M.: Kähler geometry of toric varieties and extremal metrics. Int. J. Math. 9(6), 641–651 (1998). https://doi.org/10.1142/S0129167X98000282
Apostolov, V.: The Kähler geometry of toric manifolds. Lecture Notes of CIRM winter school. http://profmath.uqam.ca/~apostolo/papers/toric-lecture-notes.pdf (2019)
Atiyah, M.F.: Convexity and commuting Hamiltonians. Bull. Lond. Math. Soc. 14(1), 1–15 (1982)
Autonne, L.: Sur les matrices hypohermitiennes et sur les matrices unitaires. Ann. de l’Université de Lyon 38, 1–77 (1915)
Berman, R.J., Darvas, T., Lu, C.H.: Regularity of weak minimizers of the K-energy and applications to properness and K-stability. Ann. Sci. Éc. Norm. Supér (4) 53(2), 267–289 (2020). https://doi.org/10.24033/asens.2422
Biquard, O., Gauduchon, P.: Hyperkähler metrics on cotangent bundles of Hermitian symmetric spaces. In: Andersen, J. E., Dupont, J., Pedersen, H., Swann, A. (eds.) Geometry and Physics (Aarhus, 1995), Lecture Notes in Pure and Applied Mathematics, vol. 184, pp. 287–298. Dekker, New York (1997)
Caffarelli, L.A.: Interior \(W^{2, p}\) estimates for solutions of the Monge–Ampère equation. Ann. Math. 131(1), 135–150 (1990)
Chen, X., Cheng, J.: On the constant scalar curvature Kähler metrics, general automorphism group. arXiv preprint arXiv:1801.05907 (2018)
Chen, B., Li, A.M., Sheng, L.: Uniform K-stability for extremal metrics on toric varieties. J. Differ. Equ. 257(5), 1487–1500 (2014). https://doi.org/10.1016/j.jde.2014.05.009
Chen, B., Li, A.M., Sheng, L.: Extremal metrics on toric surfaces. Adv. Math. 340, 363–405 (2018)
Codogni, G., Stoppa, J.: Torus equivariant K-stability. In: Codogni, G., Dervan, R., Viviani, F. (eds.) Moduli of K-stable varieties, Springer INdAM Ser., vol. 31, pp. 15–35. Springer, Cham (2019)
Delzant, T.: Hamiltoniens périodiques et images convexes de l’application moment. Bull. Soc. Math. Fr. 116(3), 315–339 (1988)
Donaldson, S.K.: Moment maps in differential geometry. In: Yau, S.-T. (ed.) Surveys in differential geometry, vol. VIII (Boston, MA, 2002), pp. 171–189. International Press, Somerville. https://doi.org/10.4310/SDG.2003.v8.n1.a6 (2003)
Donaldson, S.K.: Remarks on gauge theory, complex geometry and 4-manifold topology. In: Atiyah, M., Iagolnitzer, D. (eds.) Fields Medallists’ lectures, World Science Series, 20th Century Mathematics, vol. 5, pp. 384–403. World Scientific Publication, River Edge (1997)
Donaldson, S.K.: Scalar curvature and projective embeddings I. J. Differ. Geom. 59, 479–522 (2001)
Donaldson, S.K.: Scalar curvature and stability of toric varieties. J. Differ. Geom. 62(2), 289–349 (2002)
Donaldson, S.K.: Interior estimates for solutions of Abreu’s equation. Collect. Math. 56(2), 103–142 (2005)
Donaldson, S.K.: Constant scalar curvature metrics on toric surfaces. Geom. Funct. Anal. 19(1), 83–136 (2009)
Feng, R., Székelyhidi, G.: Periodic solutions of Abreu’s equation. Math. Res. Lett. 18(6), 1271–1279 (2011)
Fujiki, A.: Moduli space of polarized algebraic manifolds and Kähler metrics. Sugaku Expos. 5(2), 173–191 (1992)
Guillemin, V.: Kaehler structures on toric varieties. J. Differ. Geom. 40(2), 285–309 (1994). http://projecteuclid.org/euclid.jdg/1214455538
Guillemin, V.: Moment Maps and Combinatorial Invariants of Hamiltonian \(T^n\)-spaces, Progress in Mathematics, vol. 122. Birkhäuser Boston, Inc., Boston (1994)
Guillemin, V., Sternberg, S.: Convexity properties of the moment mapping. Invent. Math. 67(3), 491–513 (1982)
Hisamoto, T.: Stability and coercivity for toric polarizations. arXiv:1610.07998
Hitchin, N.J.: The self-duality equations on a Riemann surface. Proc. Lond. Math. Soc. (3) 55(1), 59–126 (1987). https://doi.org/10.1112/plms/s3-55.1.59
Hodge, T.W.S.: Hyperkähler geometry and Teichmüller space. Thesis (Ph.D.), Imperial College London (2005). Avaiable at spiral.imperial.ac.uk
Le, N.Q.: Global Hölder estimates for 2D linearized Monge–Ampère equations with right-hand side in divergence form. J. Math. Anal. Appl. 485(2), 123865 (2020)
Li, C.: Geodesic rays and stability in the cscK problem. arXiv:2001.01366 (To appear in Ann. Sci. Éc. Norm. Supér)
Magnus, J.R.: On differentiating eigenvalues and eigenvectors. Econom Theory 1(2), 179–191 (1985). http://www.jstor.org/stable/3532409
Magnus, J.R., Neudecker, H.: Matrix Differential Calculus with Applications in Statistics and Econometrics. Wiley Series in Probability and Statistics. Wiley, New York (2019)
Scarpa, C., Stoppa, J.: Scalar curvature and an infinite-dimensional hyperkähler reduction. Asian J. Math. 24(4), 671–724 (2020)
Scarpa, C., Stoppa, J.: Solutions to Donaldson’s hyperkähler reduction on a curve. J. Geom. Anal. 31, 2871–2889 (2021). https://doi.org/10.1007/s12220-020-00377-3
Takagi, T.: On an algebraic problem related to an analytic theorem of Carathéodory and Fejér and on an allied theorem of Landau. Jpn. J. Math. Trans. Abstr. 1, 83–93 (1924)
Trautwein, S.: The Donaldson hyperkähler metric on the almost-fuchsian moduli space. ArXiv:1809.00869 [math.DG]
Trudinger, N.S., Wang, X.J.: The Monge–Ampère equation and its geometric applications. Handb. Geom. Anal. 1, 467–524 (2008)
Acknowledgements
Part of this work was written while the first author was visiting the University of Illinois at Chicago. The first author wishes to thank the Department of Mathematics at UIC for kind hospitality, and particularly Julius Ross for many helpful discussions related to this work. We are grateful to Julien Keller and Vestislav Apostolov for some useful comments on an earlier version of these results. We are very grateful to the reviewer for the valuable suggestions, in particular regarding our stability result, Theorem 1.7. We would also like to thank all the participants in the Kähler geometry seminars at IGAP, Trieste.
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Scarpa, C., Stoppa, J. The HcscK equations in symplectic coordinates. Math. Z. 301, 75–113 (2022). https://doi.org/10.1007/s00209-021-02902-8
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DOI: https://doi.org/10.1007/s00209-021-02902-8