Reductive Homogeneous Spaces of the Compact Lie Group \(G_2\)

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Non-Associative Algebras and Related Topics (NAART 2020)

Part of the book series: Springer Proceedings in Mathematics & Statistics ((PROMS,volume 427))

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Abstract

The first author defended her doctoral thesis “Espacios homogéneos reductivos y álgebras no asociativas” in 2001, supervised by P. Benito and A. Elduque. This thesis contained the classification of the Lie-Yamaguti algebras with standard envelo** algebra \(\mathfrak {g}_2\) over fields of characteristic zero, which in particular gives the classification of the homogeneous reductive spaces of the compact Lie group \(G_2\). In this work we revisit this classification from a more geometrical approach. We provide too geometric models of the corresponding homogeneous spaces and make explicit some relations among them.

Partially supported by Junta de Andalucía projects FQM-336, UMA18-FEDERJA-119 and P20_01391, and by the Spanish MICINN projects PID2019-104236GB-I00/AEI/10.13039/501100011033 and PID2020-118452GB-I00, all of them with FEDER funds.

Partially supported by Spanish MICINN project PID2020-118452GB-I00 and Andalusian and ERDF projects FQM-494 and P20\(_{-}\)01391.

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Notes

  1. 1.

    Note that l and r correspond to − and \(+\), respectively, in the literature.

  2. 2.

    Be careful with the typo in that formula in [39, Proposition 2.4].

  3. 3.

    Note that, if \(J^2=-\textrm{id}\), then \(J\in \textrm{SO}(W)\) if and only if \(J\in \mathfrak {so}(W)\).

References

  1. Agricola, I.: Old and new on the exceptional group \(G_2\). Not. Am. Math. Soc. 55(8), 922–929 (2008)

    MATH  Google Scholar 

  2. Agricola, I., Borówka, A., Friedrich, T.: \(S^6\) and the geometry of nearly Kähler \(6\)-manifolds. Differ. Geom. Appl. 57, 75–86 (2018)

    Article  MATH  Google Scholar 

  3. Baez, J.C.: The octonions. Bull. Am. Math. Soc. (N.S.) 39(2), 145–205 (2002)

    Google Scholar 

  4. Benito, P., Elduque, A., Martín Herce, F.: Irreducible Lie-Yamaguti algebras of generic type. J. Pure Appl. Algebr. 215(2), 108–130 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  5. Benito, P., Draper, C., Elduque, A.: Models of the octonions and \(G_2\). Linear Algebr. Appl. 371, 333–359 (2003)

    Article  MATH  Google Scholar 

  6. Benito, P., Draper, C., Elduque, A.: Lie-Yamaguti algebras related to \(\mathfrak{g} _2\). J. Pure Appl. Algebr. 202(1–3), 22–54 (2005)

    Article  MATH  Google Scholar 

  7. Besse, A.L.: Einstein manifolds. Reprint of the 1987 edition. Classics in Mathematics, p. xii+516. Springer, Berlin (2008)

    Google Scholar 

  8. Bobieński, M., Nurowski, P.: Irreducible \(SO(3)\) geometry in dimension five. J. Reine Angew. Math. 605, 51–93 (2007)

    MathSciNet  MATH  Google Scholar 

  9. Boyer, Ch., Galicki, K.: Sasakian Geometry, Oxford Mathematical Monographs, p. 613. Oxford University Press, New York (2008)

    Google Scholar 

  10. Bremner, M., Hentzel, I.: Invariant nonassociative algebra structures on irreducible representations of simple Lie algebras. Exp. Math. 13(2), 231–256 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  11. Bryant, R.L.: Submanifolds and special structures on the octonians. J. Differ. Geom. 17(2), 185–232 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  12. Cartan, É.: Les systèmes de Pfaff, à cinq variables et les équations aux d?erivées partielles du second ordre. Ann. Sci. Éc. Norm. Supér. 27, 109–192 (1910)

    Article  MATH  Google Scholar 

  13. Cartan, É.: Les groupes réels simples, finis et continus. Ann. Sci. École Norm. Supér. 31, 263–355 (1914)

    Article  MATH  Google Scholar 

  14. Cartan, É.: Sur une classe remarquable d’espaces de Riemann. (French) Bull. Soc. Math. France 54, 214–264 (1926)

    Google Scholar 

  15. Chen, B.-Y.: Riemannian submanifolds. Handbook of Differential Geometry, vol. I, pp. 187–418. North-Holland, Amsterdam (2000)

    Google Scholar 

  16. Chen, B.-Y., Nagano, T.: Totally geodesic submanifolds of symmetric spaces. I. Duke Math. J. 44(4), 745–755 (1977)

    Google Scholar 

  17. Dixmier, J.: Certaines algèbres non associatives simples définies par la transvection des formes binaires. (French). J. Reine Angew. Math. 346, 110–128 (1984)

    Google Scholar 

  18. Doković, D.Z.: Classification of nilpotent elements in simple exceptional real Lie algebras of inner type and description of their centralizers. J. Algebr. 112(2), 503–524 (1988)

    Article  MathSciNet  MATH  Google Scholar 

  19. Draper, C.: Espacios homogéneos reductivos y álgebras no asociativas. Ph.D. thesis, Universidad de La Rioja (2001) (Spanish)

    Google Scholar 

  20. Draper Fontanals, C.: Notes on \(G_2\): the Lie algebra and the Lie group. Differ. Geom. Appl. 57, 23–74 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  21. Draper, C., Ortega, M., Palomo, F.J.: Affine connections on 3-Sasakian homogeneous manifolds. Math. Z. 294(1–2), 817–868 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  22. Dynkin, E.B.: Semisimple subalgebras of semisimple Lie algebras. (Russian) Mat. Sb. N.S. 30(72), 349–462 (3 plates) (1952)

    Google Scholar 

  23. Elduque, A., Myung, H.C.: Color algebras and affine connections on \(S^6\). J. Algebr. 149(1), 234–261 (1992)

    Article  MATH  Google Scholar 

  24. Elduque, A.: Lie algebras, Course notes, http://personal.unizar.es/elduque/files/LAElduque.pdf

  25. Engel, F.: Ein neues, dem linearen Komplexe analoges Gebilde. Leipz. Ber. 52(63–76), 220–239 (1900)

    MATH  Google Scholar 

  26. Enoyoshi, K.: Principal curvatures of homogeneous hypersurfaces in a Grassmann manifold \(\widetilde{Gr}_3(\rm Im \, O\rm )\) by the \(G_2\)-action. Tokyo J. Math. 42(2), 571–584 (2019)

    Article  MathSciNet  MATH  Google Scholar 

  27. Enoyoshi, K., Tsukada, K.: Lagrangian submanifolds of \(S^{6}\) and the associative Grassmann manifold. Kodai Math. J. 43(1), 170–192 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  28. Fernández, M., Gray, A.: Riemannian manifolds with structure group \(G_{2}\). Ann. Mat. Pura Appl. 132, 19–45 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  29. Gray, A.: Six dimensional almost complex manifolds defined by means of three-fold vector cross products. Tohoku Math. J. 21(2), 614–620 (1969)

    Google Scholar 

  30. Harvey, F.R.: Spinors and calibrations. Perspectives in Mathematics, vol. 9, pp. xiv+323. Academic Press Inc., Boston (1990). ISBN: 0-12-329650-1

    Google Scholar 

  31. Hitchin, N.: The geometry of three-forms in six dimensions. J. Differ. Geom. 55, 547–576 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  32. Klein, S.: Totally geodesic submanifolds of the exceptional Riemannian symmetric spaces of rank 2. Osaka J. Math. 47(4), 1077–1157 (2010)

    MathSciNet  MATH  Google Scholar 

  33. Kostant, B.: The principal three-dimensional subgroup and the Betti numbers of a complex simple Lie group. Am. J. Math. 81, 973–1032 (1959)

    Article  MathSciNet  MATH  Google Scholar 

  34. Leites, D., Lozhechnyk, O.: Inverses of Cartan matrices of Lie algebras and Lie superalgebras. Linear Algebr. Appl. 583, 195–256 (2019)

    Article  MathSciNet  MATH  Google Scholar 

  35. Mayanskiy, E.: The subalgebras of \(G_2\). ar**v:1611.04070 (2016)

  36. Miyaoka, R.: Geometry of \(G_2\) orbits and isoparametric hypersurfaces. Nagoya Math. J. 203, 175–189 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  37. Nakata, F.: Homotopy groups of \(G_2/{S}{p}(1)\) and \(G_2/U(2)\). Contemporary Perspectives in Differential Geometry and Its Related Fields, pp. 151–159, 2018. World Scientific Publishing, Hackensack (2017)

    Google Scholar 

  38. Nakata, F.: The Penrose type twistor correspondence for the exceptional simple Lie group \(G2\) (Aspects of submanifolds and other related fields). Notes of the Institute of Mathematical Analysis, vol. 2145, pp. 54–68 (2020). https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/255001/1/2145-08.pdf

  39. Onishchik, A.L., Vinberg, È.B. (eds.): Lie groups and Lie algebras, III. Encyclopaedia of Mathematical Sciences, vol. 1, pp. iv+248. Springer, Berlin (1994). ISBN: 3-540-54683-9

    Google Scholar 

  40. Salamon, S.: Quaternionic Kähler manifolds. Inven. Math. 67(1), 143–171 (1982)

    Article  MATH  Google Scholar 

  41. Schafer, R.D.: An introduction to nonassociative algebras. Pure and Applied Mathematics, vol. 22, pp. x+166. Academic Press, New York (1966)

    Google Scholar 

  42. Warner, F.W.: Foundations of differentiable manifolds and Lie groups. Corrected reprint of the 1971 edition. Graduate Texts in Mathematics, vol. 94, pp. ix+272. Springer, New York-Berlin (1983)

    Google Scholar 

  43. Wolf, J.A.: Complex homogeneous contact manifolds and quaternionic symmetric spaces. J. Math. Mech. 14, 1033–1047 (1965)

    MathSciNet  MATH  Google Scholar 

  44. Wolf, J.A.: The geometry and structure of isotropy irreducible homogeneous spaces. Acta Math. 120, 59–148 (1968)

    Article  MathSciNet  MATH  Google Scholar 

  45. Zhevlakov, K.A., Slin’ko, A.M., Shestakov, I.P., Shirshov, A.I.: Rings that are nearly associative. Translated from the Russian by Harry F. Smith. Pure and Applied Mathematics, vol. 104, pp. xi+371. Academic Press, Inc. [Harcourt Brace Jovanovich, Publishers], New York-London (1982)

    Google Scholar 

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Correspondence to Cristina Draper .

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Draper, C., Palomo, F.J. (2023). Reductive Homogeneous Spaces of the Compact Lie Group \(G_2\). In: Albuquerque, H., Brox, J., Martínez, C., Saraiva, P. (eds) Non-Associative Algebras and Related Topics. NAART 2020. Springer Proceedings in Mathematics & Statistics, vol 427. Springer, Cham. https://doi.org/10.1007/978-3-031-32707-0_3

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