Nous donnons une solution complète et explicite du problème d'existence de métriques kählériennes extrémales sur un orbifold torique de dimension réelle 4, dont le nombre de Betti est égal à 2. Nous montrons plus précisément que admet de telles métriques si et seulement si son polytope de Delzant rationnel — qui est alors un quadrilatère étiqueté — est -polystable, suivant la théorie générale développée dans le cas torique par S. K. Donaldson, E. Legendre, G. Székelyhidi et al., et que ces métriques sont alors ambitoriques, donc complètement explicites d'après la classification figurant dans la première partie de ce travail. Notre approche donne de surcroît une façon effective de tester la stabilité des quadrilatères étiquetés. Parmi les métriques kählériennes construites dans cet article figurent celles dont le tenseur de Bach est nul, qui sont à la fois extrémales et conformément Einstein. Nous obtenons ainsi, en dimension 4, de nouveaux exemples explicites d'orbifolds d'Einstein compacts ou de variétés d'Einstein non-compactes, complètes et lisses.
We provide an explicit resolution of the existence problem for extremal Kähler metrics on toric 4-orbifolds with second Betti number . More precisely we show that admits such a metric if and only if its rational Delzant polytope (which is a labelled quadrilateral) is K-polystable in the relative, toric sense (as studied by S. Donaldson, E. Legendre, G. Székelyhidi et al.). Furthermore, in this case, the extremal Kähler metric is ambitoric, i.e., compatible with a conformally equivalent, oppositely oriented toric Kähler metric, which turns out to be extremal as well. These results provide a computational test for the K-stability of labelled quadrilaterals.
Extremal ambitoric structures were classified locally in Part I of this work, but herein we only use the straightforward fact that explicit Kähler metrics obtained there are extremal, and the identification of Bach-flat (conformally Einstein) examples among them. Using our global results, the latter yield countably infinite families of compact toric Bach-flat Kähler orbifolds, including examples which are globally conformally Einstein, and examples which are conformal to complete smooth Einstein metrics on an open subset, thus extending the work of many authors.
DOI : 10.24033/asens.2266
Keywords: Extremal Kähler metrics, toric geometry, Einstein 4-orbifolds.
Mot clés : Métriques kählériennes extrémales, géométrie torique, orbifolds d'Einstein de dimension 4.
@article{ASENS_2015__48_5_1075_0, author = {Apostolov, Vestislav and Calderbank, David M. J. and Gauduchon, Paul}, title = {Ambitoric geometry {II:} {Extremal} toric surfaces and {Einstein} 4-orbifolds}, journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure}, pages = {1075--1112}, publisher = {Soci\'et\'e Math\'ematique de France. Tous droits r\'eserv\'es}, volume = {Ser. 4, 48}, number = {5}, year = {2015}, doi = {10.24033/asens.2266}, mrnumber = {3429476}, zbl = {1346.32007}, language = {en}, url = {http://www.numdam.org/articles/10.24033/asens.2266/} }
TY - JOUR AU - Apostolov, Vestislav AU - Calderbank, David M. J. AU - Gauduchon, Paul TI - Ambitoric geometry II: Extremal toric surfaces and Einstein 4-orbifolds JO - Annales scientifiques de l'École Normale Supérieure PY - 2015 SP - 1075 EP - 1112 VL - 48 IS - 5 PB - Société Mathématique de France. Tous droits réservés UR - http://www.numdam.org/articles/10.24033/asens.2266/ DO - 10.24033/asens.2266 LA - en ID - ASENS_2015__48_5_1075_0 ER -
%0 Journal Article %A Apostolov, Vestislav %A Calderbank, David M. J. %A Gauduchon, Paul %T Ambitoric geometry II: Extremal toric surfaces and Einstein 4-orbifolds %J Annales scientifiques de l'École Normale Supérieure %D 2015 %P 1075-1112 %V 48 %N 5 %I Société Mathématique de France. Tous droits réservés %U http://www.numdam.org/articles/10.24033/asens.2266/ %R 10.24033/asens.2266 %G en %F ASENS_2015__48_5_1075_0
Apostolov, Vestislav; Calderbank, David M. J.; Gauduchon, Paul. Ambitoric geometry II: Extremal toric surfaces and Einstein 4-orbifolds. Annales scientifiques de l'École Normale Supérieure, Série 4, Tome 48 (2015) no. 5, pp. 1075-1112. doi : 10.24033/asens.2266. http://www.numdam.org/articles/10.24033/asens.2266/
Kähler metrics on toric orbifolds, J. Differential Geom., Volume 58 (2001), pp. 151-187 http://projecteuclid.org/euclid.jdg/1090348285 (ISSN: 0022-040X) | MR | Zbl
Kähler geometry of toric varieties and extremal metrics, Internat. J. Math., Volume 9 (1998), pp. 641-651 (ISSN: 0129-167X) | DOI | MR | Zbl
Ambitoric geometry, I: Einstein metrics and extremal ambikähler structures (preprint arXiv:1302.6975, to appear in J. reine angew. Math., doi:10.1515/crelle-2014-0060 ) | MR
The geometry of weakly self-dual Kähler surfaces, Compositio Math., Volume 135 (2003), pp. 279-322 (ISSN: 0010-437X) | DOI | MR | Zbl
Hamiltonian 2-forms in Kähler geometry. I. General theory, J. Differential Geom., Volume 73 (2006), pp. 359-412 http://projecteuclid.org/euclid.jdg/1146169934 (ISSN: 0022-040X) | MR | Zbl
Hamiltonian 2-forms in Kähler geometry. II. Global classification, J. Differential Geom., Volume 68 (2004), pp. 277-345 http://projecteuclid.org/euclid.jdg/1115669513 (ISSN: 0022-040X) | MR | Zbl
Hamiltonian 2-forms in Kähler geometry. III. Extremal metrics and stability, Invent. Math., Volume 173 (2008), pp. 547-601 (ISSN: 0020-9910) | DOI | MR | Zbl
, Perspectives in Riemannian geometry (CRM Proc. Lecture Notes), Volume 40, Amer. Math. Soc., Providence, RI, 2006, pp. 1-26 | DOI | MR | Zbl
Équations du type Monge-Ampère sur les variétés kählériennes compactes, C. R. Acad. Sci. Paris Sér. A-B, Volume 283 (1976), pp. 119-121 | MR | Zbl
Sur de nouvelles variétés riemanniennes d'Einstein, Inst. Élie Cartan, Volume 6, Univ. Nancy, Nancy (1982), pp. 1-60 | MR | Zbl
, Oxford Mathematical Monographs, Oxford Univ. Press, Oxford, 2008, 613 pages (ISBN: 978-0-19-856495-9) | MR | Zbl
Compact 3-Sasakian 7-manifolds with arbitrary second Betti number, Invent. Math., Volume 131 (1998), pp. 321-344 (ISSN: 0020-9910) | DOI | MR | Zbl
Canonical Sasakian metrics, Comm. Math. Phys., Volume 279 (2008), pp. 705-733 (ISSN: 0010-3616) | DOI | MR | Zbl
Bochner-Kähler metrics, J. Amer. Math. Soc., Volume 14 (2001), pp. 623-715 (ISSN: 0894-0347) | DOI | MR | Zbl
, Algebraic geometry and topology. A symposium in honor of S. Lefschetz, Princeton Univ. Press, Princeton, N. J., 1957, pp. 78-89 | DOI | MR | Zbl
, Seminar on Differential Geometry (Ann. of Math. Stud.), Volume 102, Princeton Univ. Press, Princeton, N.J., 1982, pp. 259-290 | MR | Zbl
, Differential geometry and complex analysis, Springer, Berlin, 1985, pp. 95-114 | DOI | MR | Zbl
New Einstein-Sasaki spaces in five and higher dimensions, Phys. Rev. Lett., Volume 95 (2005), 071101 pages (ISSN: 0031-9007) | DOI | MR
Extremal metrics on toric surfaces (preprint arXiv:1008.2607 ) | MR
On conformally Kähler, Einstein manifolds, J. Amer. Math. Soc., Volume 21 (2008), pp. 1137-1168 (ISSN: 0894-0347) | DOI | MR | Zbl
Geometry of Kähler metrics and foliations by holomorphic discs, Publ. Math. IHÉS, Volume 107 (2008), pp. 1-107 (ISSN: 0073-8301) | DOI | Numdam | MR | Zbl
Hamiltoniens périodiques et images convexes de l'application moment, Bull. Soc. Math. France, Volume 116 (1988), pp. 315-339 (ISSN: 0037-9484) | DOI | Numdam | MR | Zbl
Self-dual Kähler manifolds and Einstein manifolds of dimension four, Compositio Math., Volume 49 (1983), pp. 405-433 (ISSN: 0010-437X) | Numdam | MR | Zbl
A moduli curve for compact conformally-Einstein Kähler manifolds, Compositio Math., Volume 141 (2005), pp. 1029-1080 (ISSN: 0010-437X) | DOI | MR | Zbl
Scalar curvature and stability of toric varieties, J. Differential Geom., Volume 62 (2002), pp. 289-349 http://projecteuclid.org/euclid.jdg/1090950195 (ISSN: 0022-040X) | MR | Zbl
Interior estimates for solutions of Abreu's equation, Collect. Math., Volume 56 (2005), pp. 103-142 (ISSN: 0010-0757) | MR | Zbl
Lower bounds on the Calabi functional, J. Differential Geom., Volume 70 (2005), pp. 453-472 http://projecteuclid.org/euclid.jdg/1143642909 (ISSN: 0022-040X) | MR | Zbl
Extremal metrics on toric surfaces: a continuity method, J. Differential Geom., Volume 79 (2008), pp. 389-432 http://projecteuclid.org/euclid.jdg/1213798183 (ISSN: 0022-040X) | MR | Zbl
Constant scalar curvature metrics on toric surfaces, Geom. Funct. Anal., Volume 19 (2009), pp. 83-136 (ISSN: 1016-443X) | DOI | MR | Zbl
, Fields Medallists' lectures (World Sci. Ser. 20th Century Math.), Volume 5, World Sci. Publ., River Edge, NJ, 1997, pp. 384-403 | DOI | MR
Bilinear forms and extremal Kähler vector fields associated with Kähler classes, Math. Ann., Volume 301 (1995), pp. 199-210 (ISSN: 0025-5831) | DOI | MR | Zbl
The moduli spaces and Kähler metrics of polarized algebraic varieties, Sūgaku, Volume 42 (1990), pp. 231-243 ; translation: Sugaku Expositions 5 (1992), 173–191 (ISSN: 0039-470X) | MR | Zbl
A new infinite class of Sasaki-Einstein manifolds, Adv. Theor. Math. Phys., Volume 8 (2004), pp. 987-1000 http://projecteuclid.org/euclid.atmp/1143663673 (ISSN: 1095-0761) | DOI | MR | Zbl
On modified Mabuchi functional and Mabuchi moduli space of Kähler metrics on toric bundles, Math. Res. Lett., Volume 6 (1999), pp. 547-555 (ISSN: 1073-2780) | DOI | MR | Zbl
Kaehler structures on toric varieties, J. Differential Geom., Volume 40 (1994), pp. 285-309 http://projecteuclid.org/euclid.jdg/1214455538 (ISSN: 0022-040X) | MR | Zbl
, Progress in Math., 122, Birkhäuser, 1994, 150 pages (ISBN: 0-8176-3770-2) | DOI | MR | Zbl
A momentum construction for circle-invariant Kähler metrics, Trans. Amer. Math. Soc., Volume 354 (2002), pp. 2285-2325 (ISSN: 0002-9947) | DOI | MR | Zbl
On Einstein, Hermitian 4-manifolds, J. Differential Geom., Volume 90 (2012), pp. 277-302 http://projecteuclid.org/euclid.jdg/1335230848 (ISSN: 0022-040X) | MR | Zbl
Einstein manifolds and extremal Kähler metrics, J. reine angew. Math., Volume 678 (2013), pp. 69-94 (ISSN: 0075-4102) | MR | Zbl
, Geometry and physics (Aarhus, 1995) (Lecture Notes in Pure and Appl. Math.), Volume 184, Dekker, New York, 1997, pp. 167-176 | MR | Zbl
Existence and non-uniqueness of constant scalar curvature toric Sasaki metrics, Compositio Math., Volume 147 (2011), pp. 1613-1634 (ISSN: 0010-437X) | DOI | MR | Zbl
Toric geometry of convex quadrilaterals, J. Symplectic Geom., Volume 9 (2011), pp. 343-385 http://projecteuclid.org/euclid.jsg/1310388900 (ISSN: 1527-5256) | DOI | MR | Zbl
Extremal almost-Kähler metrics, Internat. J. Math., Volume 21 (2010), pp. 1639-1662 (ISSN: 0129-167X) | DOI | MR | Zbl
Contact toric manifolds, J. Symplectic Geom., Volume 1 (2003), pp. 785-828 http://projecteuclid.org/euclid.jsg/1092749569 (ISSN: 1527-5256) | DOI | MR | Zbl
Hamiltonian torus actions on symplectic orbifolds and toric varieties, Trans. Amer. Math. Soc., Volume 349 (1997), pp. 4201-4230 (ISSN: 0002-9947) | DOI | MR | Zbl
A stronger concept of K-stability (preprint arXiv:0910.4617 )
Toric Sasaki-Einstein metrics on , Phys. Lett. B, Volume 621 (2005), pp. 208-212 (ISSN: 0370-2693) | DOI | MR | Zbl
A compact rotating gravitational instanton, Phys. Lett. B, Volume 79 (1978), pp. 235-238 | DOI
Weighted projective embeddings, stability of orbifolds, and constant scalar curvature Kähler metrics, J. Differential Geom., Volume 88 (2011), pp. 109-159 http://projecteuclid.org/euclid.jdg/1317758871 (ISSN: 0022-040X) | MR | Zbl
, Surveys in differential geometry. Volume XVI. Geometry of special holonomy and related topics (Surv. Differ. Geom.), Volume 16, Int. Press, Somerville, MA, 2011, pp. 265-324 | DOI | MR | Zbl
Relative K-stability of extremal metrics, J. Eur. Math. Soc. (JEMS), Volume 13 (2011), pp. 899-909 (ISSN: 1435-9855) | DOI | MR | Zbl
K-stability of constant scalar curvature Kähler manifolds, Adv. Math., Volume 221 (2009), pp. 1397-1408 (ISSN: 0001-8708) | DOI | MR | Zbl
Extremal metrics and -stability (2006) | MR | Zbl
Extremal metrics and -stability, Bull. Lond. Math. Soc., Volume 39 (2007), pp. 76-84 (ISSN: 0024-6093) | DOI | MR | Zbl
The Geometry and Topology of Three-Manifolds (1980) (mimeographed notes, http://library.msri.org/books/gt3m/PDF/1.pdf )
Kähler-Einstein metrics with positive scalar curvature, Invent. Math., Volume 130 (1997), pp. 1-37 (ISSN: 0020-9910) | DOI | MR | Zbl
Extremal Kähler metrics on minimal ruled surfaces, J. reine angew. Math., Volume 502 (1998), pp. 175-197 (ISSN: 0075-4102) | DOI | MR | Zbl
On the pseudo-conformal geometry of a Kähler manifold, Math. Z., Volume 157 (1977), pp. 265-270 (ISSN: 0025-5874) | DOI | MR | Zbl
Calabi's conjecture and some new results in algebraic geometry, Proc. Nat. Acad. Sci. U.S.A., Volume 74 (1977), pp. 1798-1799 (ISSN: 0027-8424) | DOI | MR | Zbl
, Differential geometry: partial differential equations on manifolds (Los Angeles, CA, 1990) (Proc. Sympos. Pure Math.), Volume 54, Amer. Math. Soc., Providence, RI, 1993, pp. 1-28 | MR | Zbl
-stability on toric manifolds, Proc. Amer. Math. Soc., Volume 136 (2008), pp. 3301-3307 (ISSN: 0002-9939) | DOI | MR | Zbl
Relative -stability and modified -energy on toric manifolds, Adv. Math., Volume 219 (2008), pp. 1327-1362 (ISSN: 0001-8708) | DOI | MR | Zbl
Cité par Sources :