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Hopf conjecture holds for analytic, k-basic Finsler tori without conjugate points

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Abstract

We show that analytic, k-basic Finsler metrics in the two torus without conjugate points are analytically integrable, in the sense that the unit tangent bundle of the metric admits an analytic foliation by invariant Lagrangian graphs. This result, combined with the fact that C 1,L integrable k-basic Finsler metrics in the two torus have zero flag curvature (Barbosa-Ruggiero [19]) implies that analytic k-basic Finsler metrics in two tori without conjugate points are flat, a positive answer to the so-called Hopf conjecture for tori without conjugate points. Since there are well known examples of non flat tori without conjugate points (Busemann was the first to show such examples) the Hopf conjecture is not true if we drop the k-basic assumption. As for higher dimensional tori, a quite simple argument based on Schur’s Lemma shows that the only Finsler, k-basic (3 + m)-tori are the flat ones for every m ≥ 0.

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References

  1. H. Akbar-Zadeh. Sur les espaces de Finsler à courbures sectionnelles constantes. Acad. Roy. Belg. Bull. C1. Sci. (5), 74 (1988), 281–322.

    MathSciNet  MATH  Google Scholar 

  2. D. Bao, S.-S. Chern and Z. Shen. An Introduction to Riemann-Finsler Geometry. Springer, New York (2000).

    Book  MATH  Google Scholar 

  3. D. Bao and C. Robles. On Ricci and flag curvatures in Finsler geometry, in “A Sampler of Riemann-Finsler Geometry”, MSRI Series, 50 (2004), 197–259.

    MathSciNet  Google Scholar 

  4. M.L. Bialy. Rigidity for periodic magnetic fields. Ergod. Th. & Dynam. Sys., 20 (2000), 1619–1626.

    Article  MathSciNet  MATH  Google Scholar 

  5. D. Burago and S. Ivanov. Riemannian tori without conjugate points are flat. Geom. Funct. Anal., 4 (1994), 259–269.

    Article  MathSciNet  MATH  Google Scholar 

  6. H. Busemann. The Geometry of Finsler spaces. Bulletin of the AMS, 56 (1950), 5–16.

    Article  MathSciNet  MATH  Google Scholar 

  7. H. Busemann. The Geometry of Geodesics. Pure and Applied Mathematics, Vol. 6, Academic Press, New York, NY (1955).

    Google Scholar 

  8. D. Chen. On total flexibility of local structures of Finsler tori without conjugate points. Preprint, arXiv: 1310.7299 (2013).

    Google Scholar 

  9. G. Contreras and R. Iturriaga. Convex Hamiltonians without conjugate points. Ergod. Th. & Dynam. Sys., 19 (1999), 901–952.

    Article  MathSciNet  MATH  Google Scholar 

  10. E. Ghys. Rigidité différentiable des groupes Fuchsiens. Publications Mathématiques I.H.E.S., 78 (1993), 163–185.

    Article  MathSciNet  MATH  Google Scholar 

  11. C. Croke and B. Kleiner. On tori without conjugate points. Invent. Math., 120 (1995), 241–257.

    Article  MathSciNet  MATH  Google Scholar 

  12. A. Fathi. Oral communication.

  13. P. Foulon and R. Ruggiero. A first integral for C8, k-basic Finsler surfaces and applications to rigidity. Preprint PUC-Rio (2015).

    Google Scholar 

  14. L.W. Green. Surfaces without conjugate points. Transactions of the American Mathematical Society, 76 (1954), 529–546.

    Article  MathSciNet  MATH  Google Scholar 

  15. J.B. Gomes and R. Ruggiero. Rigidity of surfaces whose geodesic flows preserve smooth foliations of codimension 1. Proceedings of the American Mathematical Society, 135 (2007), 507–515.

    Article  MathSciNet  MATH  Google Scholar 

  16. J.B. Gomes and R. Ruggiero. Rigidity of magnetic flows for compact surfaces. Comptes Rendus Acad. Sci. Paris, Ser. I, 346 (2008), 313–316.

    Article  MathSciNet  MATH  Google Scholar 

  17. J.B. Gomes and R. Ruggiero. Smooth k-basic Finsler surfaces with expansive geodesic flows are Riemannian. Houston J. Math., 37(3) (2011), 793–806.

    MathSciNet  MATH  Google Scholar 

  18. J.B. Gomes and R. Ruggiero. On Finsler surfaces without conjugate points. Ergod. Th. & Dynam. Sys., 33 (2013), 455–474.

    Article  MathSciNet  MATH  Google Scholar 

  19. J.B. Gomes and R. Ruggiero. Weak integrability of Hamiltonians on the two torus and rigidity. Nonlinearity, 26 (2013), 2109–2129.

    Article  MathSciNet  MATH  Google Scholar 

  20. J. Heber. On the geodesic flow of tori without conjugate points. Math. Z., 216(2) (1994), 209–216.

    Article  MathSciNet  MATH  Google Scholar 

  21. G.A. Hedlund. Geodesics on a two dimensional Riemannian manifold with periodic coefficients. Ann. Math., 33 (1932), 719–739.

    Article  MathSciNet  Google Scholar 

  22. E. Hopf. Closed surfaces without conjugate points. Proceedings of the National Academy of Sciences, 34 (1948), 47–51.

    Article  MathSciNet  MATH  Google Scholar 

  23. S. Krantz and H. Parks. A Primer of real analytic functions. Second Edition. Birkhäusser, Boston (2002).

    Book  MATH  Google Scholar 

  24. Y. Mitsumatsu. A relation between the topological invariance of the Godbillon-Vey invariant and the differentiability of Anosov foliations. Foliations (Tokyo, 1983) 159-167 Advanced Studies in Pure Mathematics, 5, North Holland, Amsterdam (1985).

    Google Scholar 

  25. G.P. Paternain. Geodesic flows. Birkhäuser, Boston (1999).

    Book  MATH  Google Scholar 

  26. Z. Shen. Lectures on Finsler Geometry. World Scientific Pub. Co. Inc. (2001), 307 pp.

  27. N. Zinov’ev. Examples of Finsler metrics without conjugate points: metrics of revolution. St. Petersburg Math. J., 20 (2009), 361–379.

    Article  MathSciNet  MATH  Google Scholar 

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Correspondence to Rafael O. Ruggiero.

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Gomes, J.B., Dias Carneiro, M.J. & Ruggiero, R.O. Hopf conjecture holds for analytic, k-basic Finsler tori without conjugate points. Bull Braz Math Soc, New Series 46, 621–644 (2015). https://doi.org/10.1007/s00574-015-0106-x

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  • DOI: https://doi.org/10.1007/s00574-015-0106-x

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