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Lusternik–Schnirelmann theory and closed Reeb orbits

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We develop a variant of Lusternik–Schnirelmann theory for the shift operator in equivariant Floer and symplectic homology. Our key result is that the spectral invariants are strictly decreasing under the action of the shift operator when periodic orbits are isolated. As an application, we prove new multiplicity results for simple closed Reeb orbits on the standard contact sphere, the unit cotangent bundle to the sphere and some other contact manifolds. We also show that the lower Conley–Zehnder index enjoys a certain recurrence property and revisit and reprove from a different perspective a variant of the common jump theorem of Long and Zhu. This is the second, combinatorial ingredient in the proof of the multiplicity results.

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References

  1. Abbondandolo, A.: Morse Theory for Hamiltonian Systems. Research Notes in Mathematics, vol. 425. Chapman & Hall/CRC, Boca Raton (2001)

    Book  MATH  Google Scholar 

  2. Abbondandolo, A., Schwarz, M.: Floer homology of cotangent bundles and the loop product. Geom. Topol. 14, 1569–1722 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  3. Abreu, M., Macarini, L.: Dynamical convexity and elliptic periodic orbits for Reeb flows. Math. Ann. 369, 331–386 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  4. Abreu, M., Macarini, L.: Multiplicity of periodic orbits for dynamically convex contact forms. J. Fixed Point Rheory Appl. 19, 175–204 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  5. Albers, P., Gutt, J., Hein, D.: Periodic Reeb orbits on prequantization bundles. J. Mod. Dyn. 12, 123–150 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  6. Ambrosetti, A., Mancini, G.: On a theorem by Ekeland and Lasry concerning the number of periodic Hamiltonian trajectories. J. Differ. Equ. 43, 249–256 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  7. Arnold, V.I.: Mathematical Methods of Classical Mechanics. Springer, Berlin (1989)

    Book  Google Scholar 

  8. Arnold, V.I., Givental, A.B.: Symplectic geometry. In: Dynamical Systems, IV, Encyclopaedia Math. Sci., 4, 1–138, Springer, Berlin (2001)

  9. Arnaud, M.-C.: Existence d’orbites périodiques complétement elliptiques des hamiltoniens convexes présentant certaines symétries. C. R. Acad. Sci. Paris Sér. I Math. 328, 1035–1038 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  10. Ballmann, W., Thorbergsson, G., Ziller, W.: Existence of closed geodesics on positively curved manifolds. J. Differ. Geom. 18, 221–252 (1983)

    Article  MathSciNet  MATH  Google Scholar 

  11. Bangert, V., Long, Y.: The existence of two closed geodesics on every Finsler 2-sphere. Math. Ann. 346, 335–366 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  12. Barge, J., Ghys, E.: Cocycles d’Euler et de Maslov. Math. Ann. 294, 235–265 (1992)

    Article  MathSciNet  MATH  Google Scholar 

  13. Batoréo, M.: On the rigidity of the coisotropic Maslov index on certain rational symplectic manifolds. Geom. Dedicata. 165, 135–156 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  14. Bourgeois, F.: A Morse–Bott Approach to Contact Homology, Ph.D. dissertation, Stanford University, Stanford, Calif., (2002)

  15. Bourgeois, F., Oancea, A.: Symplectic homology, autonomous Hamiltonians, and Morse-Bott moduli spaces. Duke Math. J. 146, 71–174 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  16. Bourgeois, F., Oancea, A.: Fredholm theory and transversality for the parametrized and for the \(S^1\)-invariant symplectic action. J. Eur. Math. Soc. (JEMS) 12, 1181–1229 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  17. Bourgeois, F., Oancea, A.: The index of Floer moduli problems for parametrized action functionals. Geom. Dedicata. 165, 5–24 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  18. Bourgeois, F., Oancea, A.: The Gysin exact sequence for \(S^1\)-equivariant symplectic homology. J. Topol. Anal. 5, 361–407 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  19. Bourgeois, F., Oancea, A.: \(S^1\)-equivariant symplectic homology and linearized contact homology. Int. Math. Res. Not. IMRN 2017, 3849–3937 (2017)

    MATH  MathSciNet  Google Scholar 

  20. Bramham, B.: Pseudo-rotations with sufficiently Liouvillean rotation number are \(C^0\)-rigid. Invent. Math. 199, 561–580 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  21. Cassels, J.W.S.: An Introduction to Diophantine Approximation. Cambridge Tracts in Mathematics and Mathematical Physics, vol. 45. Cambridge University Press, New York (1957)

    MATH  Google Scholar 

  22. Chance, M., Ginzburg, V.L., Gürel, B.Z.: Action-index relations for perfect Hamiltonian diffeomorphisms. J. Symplectic Geom. 11, 449–474 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  23. Cieliebak, K., Frauenfelder, U., Oancea, A.: Rabinowitz Floer homology and symplectic homology. Ann. Sci. Éc. Norm. Supér. (4) 43, 957–1015 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  24. Colin, V., Honda, K.: Reeb vector fields and open book decompositions. J. Eur. Math. Soc. (JEMS) 15, 443–507 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  25. Cristofaro-Gardiner, D., Hutchings, M.: From one Reeb orbit to two. J. Differ. Geom. 102, 25–36 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  26. Croke, C.B., Weinstein, A.: Closed curves on convex hypersurfaces and periods of nonlinear oscillations. Invent. Math. 64, 199–202 (1981)

    Article  MathSciNet  MATH  Google Scholar 

  27. Dell’Antonio, G., D’Onofrio, B., Ekeland, I.: Periodic solutions of elliptic type for strongly nonlinear Hamiltonian systems. In: The Floer Memorial Volume, 327–333, Progr. Math., 133, Birkhäuser, Basel (1995)

  28. Duan, H., Long, Y., Wang, W.: The enhanced common index jump theorem for symplectic paths and non-hyperbolic closed geodesics on Finsler manifolds. Calc. Var. Partial Differ. Equ. 55, 55–145 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  29. Duan, H., Liu, H., Long, Y., Wang, W.: Non-hyperbolic closed characteristics on non-degenerate star-shaped hypersurfaces in \({\mathbb{R}}^{2n}\). Acta Math. Sin. Engl. Ser. 34, 1–18 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  30. Ekeland, I.: Convexity Methods in Hamiltonian Mechanics. Springer, Berlin (1990)

    Book  MATH  Google Scholar 

  31. Ekeland, I., Hofer, H.: Convex Hamiltonian energy surfaces and their periodic trajectories. Commun. Math. Phys. 113, 419–469 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  32. Ekeland, I., Hofer, H.: Symplectic topology and Hamiltonian dynamics. Math. Z. 200, 355–378 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  33. Ekeland, I., Lasry, J.-M.: On the number of periodic trajectories for a Hamiltonian flow on a convex energy surface. Ann. Math. (2) 112, 283–319 (1980)

    Article  MathSciNet  MATH  Google Scholar 

  34. Espina, J.: On the mean Euler characteristic of contact structures. Int. J. Math. 25, 1450046 (2014). (36 pp)

    Article  MathSciNet  MATH  Google Scholar 

  35. Fadell, E., Rabinowitz, P.: Generalized cohomological theories for Lie group actions with an application to bifurcation questions for Hamiltonian systems. Inv. Math. 45, 139–174 (1978)

    Article  MathSciNet  MATH  Google Scholar 

  36. Floer, A.: Cuplength estimates on Lagrangian intersections. Commun. Pure Appl. Math. 42, 335–356 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  37. Floer, A.: Symplectic fixed points and holomorphic spheres. Commun. Math. Phys. 120, 575–611 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  38. Ginzburg, V.L.: Coisotropic intersections. Duke Math. J. 140, 111–163 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  39. Ginzburg, V.L.: The Conley conjecture. Ann. Math. (2) 172, 1127–1180 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  40. Ginzburg, V.L.: My contact homology shopping list, Preprint arXiv:1412.7999 (not intended for journal publication)

  41. Ginzburg, V.L., Gören, Y.: Iterated index and the mean Euler characteristic. J. Topol. Anal. 7, 453–481 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  42. Ginzburg, V.L., Gürel, B.Z.: Action and index spectra and periodic orbits in Hamiltonian dynamics. Geom. Topol. 13, 2745–2805 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  43. Ginzburg, V.L., Gürel, B.Z.: On the generic existence of periodic orbits in Hamiltonian dynamics. J. Mod. Dyn. 4, 595–610 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  44. Ginzburg, V.L., Gürel, B.Z.: Periodic orbits of twisted geodesic flows and the Weinstein-Moser theorem. Comment. Math. Helv. 84, 865–907 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  45. Ginzburg, V.L., Gürel, B.Z.: Local Floer homology and the action gap. J. Symplectic Geom. 8, 323–357 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  46. Ginzburg, V.L., Gürel, B.Z.: Hyperbolic fixed points and periodic orbits of Hamiltonian diffeomorphisms. Duke Math. J. 163, 565–590 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  47. Ginzburg, V.L., Gürel, B.Z.: The Conley conjecture and beyond. Arnold Math. J. 1, 299–337 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  48. Ginzburg, V.L., Gürel, B.Z., Macarini, L.: On the Conley conjecture for Reeb flows. Int. J. Math. 26, 1550047 (2015). https://doi.org/10.1142/S0129167X15500470. (22 pages)

    Article  MathSciNet  MATH  Google Scholar 

  49. Ginzburg, V.L., Gürel, B.Z., Macarini, L.: Multiplicity of closed Reeb orbits on prequantization bundles. J. Math, Isr (2018). https://doi.org/10.1007/s11856-018-1769-y

    Book  MATH  Google Scholar 

  50. Ginzburg, V.L., Hein, D., Hryniewicz, U.L., Macarini, L.: Closed Reeb orbits on the sphere and symplectically degenerate maxima. Acta Math. Vietnam. 38, 55–78 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  51. Ginzburg, V.L., Kerman, E.: Homological resonances for Hamiltonian diffeomorphisms and Reeb flows. Int. Math. Res. Not. IMRN 2010, 53–68 (2010)

    MathSciNet  MATH  Google Scholar 

  52. Ginzburg, V.L., Shon, J.: On the filtered symplectic homology of prequantization bundles. Int. J. Math. (2018). https://doi.org/10.1142/S0129167X18500714

    Article  MathSciNet  MATH  Google Scholar 

  53. Goresky, M., Hingston, N.: Loop products and closed geodesics. Duke Math. J. 150, 117–209 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  54. Grayson, M.A.: Shortening embedded curves. Ann. Math. (2) 129, 71–111 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  55. Gromoll, D., Meyer, W.: Periodic geodesics on compact Riemannian manifolds. J. Differ. Geom. 3, 493–510 (1969)

    Article  MathSciNet  MATH  Google Scholar 

  56. Guillemin, V., Ginzburg, V., Karshon, Y.: Moment Maps, Cobordisms, and Hamiltonian Group Actions, Mathematical Surveys and Monographs, 98. American Mathematical Society, Providence, RI (2002)

  57. Gürel, B.Z.: On non-contractible periodic orbits of Hamiltonian diffeomorphisms. Bull. Lond. Math. Soc. 45, 1227–1234 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  58. Gürel, B.Z.: Perfect Reeb flows and action-index relations. Geom. Dedicata. 174, 105–120 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  59. Gutt, J.: Generalized Conley-Zehnder index. Ann. Fac. Sci. Toulouse Math. 23, 907–932 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  60. Gutt, J.: The positive equivariant symplectic homology as an invariant for some contact manifolds. J. Sympl. Geom. 15, 1019–1069 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  61. Gutt, J., Hutchings, M.: Symplectic capacities from positive \(S^1\)-equivariant symplectic homology. Algebraic Geom. Topol. 18, 3537–3600 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  62. Gutt, J., Kang, J.: On the minimal number of periodic orbits on some hypersurfaces in \({\mathbb{R}}^{2n}\). Ann. Inst. Fourier 66, 2485–2505 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  63. Harris, A., Paternain, G.: Dynamically convex Finsler metrics and \(J\)-holomorphic embedding of asymptotic cylinders. Ann. Glob. Anal. Geom. 34, 115–134 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  64. Hofer, H.: Lusternik-Schnirelmann theory for Lagrangian intersections. Ann. Inst. H. Poincaré Anal. Non Linéaire 5, 465–499 (1988)

    Article  MathSciNet  MATH  Google Scholar 

  65. Hofer, H., Salamon, D.: Floer homology and Novikov rings. In: The Floer Memorial Volume, 483–524, Progr. Math., 133, Birkhäuser, Basel (1995)

  66. Hofer, H., Wysocki, K., Zehnder, E.: The dynamics on three-dimensional strictly convex energy surfaces. Ann. Math. (2) 148, 197–289 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  67. Hofer, H., Zehnder, E.: Symplectic Invariants and Hamiltonian Dynamics. Birkäuser, Basel (1994)

    Book  MATH  Google Scholar 

  68. Howard, W.: Action selectors and the fixed point set of a Hamiltonian diffeomorphism, Preprint arXiv:1211.0580

  69. Howard, W.: The Monster Tower and Action Selectors, Ph.D. Thesis – University of California, Santa Cruz, (2013), 101 pp

  70. Hryniewicz, U., Macarini, L.: Local contact homology and applications. J. Topol. Anal. 7, 167–238 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  71. Katok, A.B.: Ergodic perturbations of degenerate integrable Hamiltonian systems. Izv. Akad. Nauk SSSR Ser. Mat. 37, 539–576 (1973)

    MathSciNet  Google Scholar 

  72. Kerman, E.: Rigid constellations of closed Reeb orbits. Compos. Math. 153, 2394–2444 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  73. Kwon, M., van Koert, O.: Brieskorn manifolds in contact topology. Bull. Lond. Math. Soc. 48, 173–241 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  74. Lê, H.V., Ono, K.: Cup-length estimates for symplectic fixed points, in Contact and Symplectic Geometry (Cambridge, 1994), 268–295, Publ. Newton Inst., 8, Cambridge Univ. Press, Cambridge, (1996)

  75. Li, W.: A module structure on the symplectic Floer cohomology. Commun. Math. Phys. 211, 137–151 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  76. Liu, H., Long, Y.: The existence of two closed characteristics on every compact star-shaped hypersurface in \({\mathbb{R}}^4\). Acta Math. Sin. (Engl. Ser.) 32, 40–53 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  77. Liu, C.-G., Long, Y., Zhu, C.: Multiplicity of closed characteristics on symmetric convex hypersurfaces in \({\mathbb{R}}^{2n}\). Math. Ann. 323, 201–215 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  78. Long, Y.: Maslov-type index, degenerate critical points, and asymptotically linear Hamiltonian systems. Sci. China Ser. A 33, 1409–1419 (1990)

    MathSciNet  MATH  Google Scholar 

  79. Long, Y.: A Maslov-type index theory for symplectic paths. Topol. Methods Nonlinear Anal. 10, 47–78 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  80. Long, Y.: Index Theory for Symplectic Paths with Applications. Birkhäuser, Basel (2002)

    Book  MATH  Google Scholar 

  81. Long, Y., Lui, H., Wang, W.: Resonance identities for closed characteristics on compact star-shaped hypersurfaces in \({\mathbb{R}}^{2n}\). J. Funct. Anal. 266, 5598–5638 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  82. Long, Y., Zhu, C.: Closed characteristics on compact convex hypersurfaces in \({\mathbb{R}}^{2n}\). Ann. Math. (2) 155, 317–368 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  83. Lusternik, L., Schnirelmann, L.: Méthods Topologiques dans les Problèmes Variationnels. Hermann, Paris (1937)

    MATH  Google Scholar 

  84. McDuff, D., Salamon, D.: J-holomorphic Curves and Symplectic Topology, vol. 52. Colloquium Publications AMS, Providence, RI (2004)

    MATH  Google Scholar 

  85. McLean, M.: Local Floer homology and infinitely many simple Reeb orbits. Algebraic Geom. Topol. 12, 1901–1923 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  86. Poźniak, M.: Floer homology, Novikov rings and clean intersections, in Northern California Symplectic Geometry Seminar, 119–181, Amer. Math. Soc. Transl. Ser. 2, 196, AMS, Providence, RI, (1999)

  87. Rademacher, H.B.: On a generic property of geodesic flows. Math. Ann. 298, 101–116 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  88. Rademacher, H.B.: A sphere theorem for non-reversible Finsler metric. Math. Ann. 328, 373–387 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  89. Ritter, A.: Topological quantum field theory structure on symplectic cohomology. J. Topol. 6, 391–489 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  90. Robbin, J., Salamon, D.: The Maslov index for paths. Topology 32, 827–844 (1993)

    Article  MathSciNet  MATH  Google Scholar 

  91. Salamon, D.A.: Morse theory, the Conley index and Floer homology. Bull. Lond. Math. Soc. 22, 113–140 (1990)

    Article  MathSciNet  MATH  Google Scholar 

  92. Salamon, D.A.: Lectures on Floer homology. In: Symplectic Geometry and Topology, IAS/Park City Math. Ser., vol. 7, Am. Math. Soc., Providence, RI, 143–229 (1999)

  93. Salamon, D., Zehnder, E.: Morse theory for periodic solutions of Hamiltonian systems and the Maslov index. Commun. Pure Appl. Math. 45, 1303–1360 (1992)

    Article  MathSciNet  MATH  Google Scholar 

  94. Schwarz, M.: A quantum cup-length estimate for symplectic fixed points. Invent. Math. 133, 353–397 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  95. Viterbo, C.: Equivariant Morse theory for starshaped Hamiltonian systems. Trans. Am. Math. Soc. 311, 621–655 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  96. Viterbo, C.: The cup-product on the Thom–Smale–Witten complex, and Floer cohomology. In: The Floer Memorial Volume, 609–625, Progr. Math., 133, Birkhäuser, Basel, (1995)

  97. Viterbo, C.: Some remarks on Massey products, tied cohomology classes, and the Lusternik-Schnirelmann category. Duke Math. J. 86, 547–564 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  98. Viterbo, C.: Functors and computations in Floer cohomology, I. Geom. Funct. Anal. 9, 985–1033 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  99. Wang, W.: On a conjecture of Anosov. Adv. Math. 230, 1597–1617 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  100. Wang, W.: Closed characteristics on compact convex hypersurfaces in \({\mathbb{R}}^8\). Adv. Math. 297, 93–148 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  101. Wang, W.: Existence of closed characteristics on compact convex hypersurfaces in \({\mathbb{R}}^{2n}\). Calc. Var. Partial Differ. Equ. 55, 1–25 (2016)

    Article  MathSciNet  Google Scholar 

  102. Wang, W., Hu, X., Long, Y.: Resonance identity, stability, and multiplicity of closed characteristics on compact convex hypersurfaces. Duke Math. J. 139, 411–462 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  103. Williamson, J.: On the algebraic problem concerning the normal forms of linear dynamical systems. Am. J. Math. 58, 141–163 (1936)

    Article  MathSciNet  MATH  Google Scholar 

  104. Usher, M.: Spectral numbers in Floer theories. Compos. Math. 144, 1581–1592 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  105. Ziller, W.: Geometry of the Katok examples. Ergodic Theory Dyn. Syst. 3, 135–157 (1983)

    Article  MathSciNet  MATH  Google Scholar 

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Acknowledgements

The authors are grateful to Alberto Abbondandolo, Fréderic Bourgeois, River Chiang, Jean Gutt, Umberto Hryniewicz, Ely Kerman, Leonardo Macarini, Marco Mazzucchelli, Yaron Ostrover, Jeongmin Shon, Otto van Koert and the referee for useful comments, remarks and discussions. This project greatly benefited from the Workshop on Conservative Dynamics and Symplectic Geometry held at IMPA, Rio de Janeiro in August 2015. The authors would like to thank the organizers (Henrique Bursztyn, Leonardo Macarini, and Marcelo Viana) of the workshop. A part of this work was carried out while the first author was visiting the National Cheng Kung University (NCKU), Taiwan, and he would like to thank the NCKU for its warm hospitality and support.

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The work is partially supported by NSF CAREER award DMS-1454342 (Başak Z. Gürel) and NSF grants DMS-1414685 (Başak Z. Gürel) and DMS-1308501 (Viktor L. Ginzburg)

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Ginzburg, V.L., Gürel, B.Z. Lusternik–Schnirelmann theory and closed Reeb orbits. Math. Z. 295, 515–582 (2020). https://doi.org/10.1007/s00209-019-02361-2

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