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On a variational problem for curves in Lie sphere geometry

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Abstract

Let \(\Lambda \) be the unit tangent bundle of the unit 3-sphere acted on transitively by the contact group of Lie sphere transformations. We study the Lie sphere geometry of generic curves in \(\Lambda \) which are everywhere transversal to the contact distribution of \(\Lambda \). By the method of moving frames, we prove that such curves can be parametrized by a Lie-invariant parameter, the Lie arclength, and that in this parametrization they are uniquely determined, up to Lie sphere transformation, by four local invariants, the Lie curvatures. We then consider the simplest Lie-invariant functional on generic transversal curves defined by integrating the differential of the Lie arclength. The corresponding Euler–Lagrange equations are computed and the critical curves are characterized in terms of their Lie curvatures. In our discussion, we adopt Griffiths’ exterior differential systems approach to the calculus of variations.

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Data Availibility Statement

No datasets were generated or analysed during the current study.

Notes

  1. To be specified in Section 3.

  2. See (2.9) in Section 2.

References

  1. Barut, A.O., Zeni, J.R., Laufer, A.: The exponential map for the conformal group \({\rm O}(2,4)\). J. Phys. A 27(15), 5239 (1994)

    Article  MathSciNet  Google Scholar 

  2. Blaschke, W.: Vorlesungen über Differentialgeometrie. III: Differentialgeometrie der Kreise und Kugeln, Grundlehren der mathematischen Wissenschaften, 29, Springer, Berlin, (1929)

  3. Bryant, R.L.: On notions of equivalence of variational problems with one independent variable. Contemp. Math. 68, 65–76 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  4. Bryant, R.L., Chern, S.S., Gardner, R.B., Goldschmidt, H.L., Griffiths, P.A.: Exterior differential systems. Springer-Verlag, New York (1991)

    Book  MATH  Google Scholar 

  5. Bryant, R.L., Griffiths, P.A.: Reduction for constrained variational problems and \(\int {{\frac{k^2}{2}}}\). Amer. J. Math. 108, 525–570 (1986)

    Article  MathSciNet  Google Scholar 

  6. Bryant, R. L., Gardner, R. B.: Control structures. Geometry in nonlinear control and differential inclusions (Warsaw, 1993), 111–121. Banach Center Publ., 32, Polish Academy of Sciences, Institute of Mathematics, Warsaw, (1995)

  7. Burstall, F., Hertrich-Jeromin, U.: Harmonic maps in unfashionable geometries. Manuscripta Math. 108, 171–189 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  8. Burstall, F., Hertrich-Jeromin, U., Pember, M., Rossman, W.: Polynomial conserved quantities of lie applicable surfaces. Manuscripta Math. 158(3–4), 505–546 (2019)

    Article  MathSciNet  MATH  Google Scholar 

  9. Calini, A., Ivey, T.: Integrable geometric flows for curves in pseudoconformal \(S^3\), J. Geom. Phys. 166 (2021), Paper No. 104249, 17 pp

  10. Cecil, T.E., Chern, S.S.: Tautness and Lie sphere geometry. Math. Ann. 278, 381–399 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  11. Cecil, T.E., Chern, S.S.: Dupin submanifolds in Lie sphere geometry, Proceedings Tianjin 1986–87. Lecture Notes in Mathematics, vol. 1369. Springer, New York (1989)

  12. Cecil, T.E.: Lie sphere geometry: with applications to submanifolds. Springer-Verlag, New York (1992)

    Book  MATH  Google Scholar 

  13. Cecil, T.E., Jensen, G.R.: Dupin hypersurfaces with three principal curvatures. Invent. Math. 132, 121–178 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  14. Cecil, T.E., Jensen, G.R.: Dupin hypersurfaces with four principal curvatures. Geometriae Ded. 79, 1–49 (2000)

    Article  MathSciNet  Google Scholar 

  15. Dzhalilov, A., Musso, E., Nicolodi, L.: Conformal geometry of timelike curves in the (1+2)-Einstein universe. Nonlinear Anal. 143, 224–255 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  16. Eshkobilov, O., Musso, E., Nicolodi, L.: The geometry of conformal timelike geodesics in the Einstein universe J. Math. Anal. Appl. 495 (2021), no. 2, Paper No. 124730, 32 pp

  17. Ferapontov, E.: Lie sphere geometry and integrable systems. Tohoku Math. J. (2) 52, 199–233 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  18. Ferrández, A., Giménez, A., Lucas, P.: Geometrical particle models on 3d null curves. Phys. Lett. B 543, 311–317 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  19. Grant, J.D., Musso, E.: Coisotropic variational problems. J. Geom. Phys. 50, 303–338 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  20. Griffiths, P.A.: Exterior differential systems and the calculus of variations, Progress in Mathematics, 25. Birkhäuser, Boston (1982)

    Google Scholar 

  21. Hsu, L.: Calculus of variations via the Griffiths formalism. J. Differential Geom. 36, 551–589 (1992)

    Article  MathSciNet  MATH  Google Scholar 

  22. Ivey, T. A., Landsberg, J. M.: Cartan for beginners, Grad. Stud. Math., 175, American Mathematical Society, Providence, RI, (2016)

  23. Jensen, G. R., Musso, E., Nicolodi, L.: The geometric Cauchy problem for the membrane shape equation, J. Phys. A 47 (2014), no. 49, 495201, 22 pp

  24. Jensen, G.R., Musso, E., Nicolodi, L.: Surfaces in Classical Geometries. Universitext, Springer, Cham, A Treatment by Moving Frames (2016)

    Book  MATH  Google Scholar 

  25. Lie, S.: Über Komplexe, insbesondere Linien-und Kugelkomplexe, mit Anwendung auf der Theorie der partieller Differentialgleichungen. Math. Ann. 5(145–208), 209–256 (1872)

    Article  MathSciNet  Google Scholar 

  26. Lie, S., Scheffers, G.: Geometrie der Berührungstransformationen. Teubner, Leipzig (1896)

    MATH  Google Scholar 

  27. Miyaoka, R.: Dupin hypersurfaces and a a Lie invariant. Kodai Math. J. 12(2), 228–256 (1989)

    Article  MathSciNet  Google Scholar 

  28. Miyaoka, R.: Lie contact structures and normal Cartan connections. Kodai Math. J. 14(1), 13–41 (1991)

    MathSciNet  MATH  Google Scholar 

  29. Musso, E.: The conformal arclength functional. Math. Nachr. 165, 107–131 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  30. Musso, E., Nicolodi, L.: On the Cauchy problem for the integrable system of Lie minimal surfaces. J. Math. Phys. 46(11), 3509–3523 (2005)

    Article  MathSciNet  Google Scholar 

  31. Musso, E., Nicolodi, L.: Deformation and applicability of surfaces in Lie sphere geometry. Tohoku Math. J. (2) 58(2), 161–187 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  32. Musso, E., Nicolodi, L.: Closed trajectories of a particle model on null curves in anti-de Sitter 3-space. Classical Quantum Gravity 24(22), 5401–5411 (2007)

    Article  MathSciNet  Google Scholar 

  33. Musso, E., Nicolodi, L.: Reduction for constrained variational problems on 3-dimensional null curves. SIAM J. Control. Optim. 47(3), 1399–1414 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  34. Musso, E., Nicolodi, L.: Quantization of the conformal arclength functional on space curves. Comm. Anal. Geom. 25(1), 209–242 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  35. Musso, E., Nicolodi, L., Salis, F.: On the Cauchy-Riemann geometry of transversal curves in the 3-sphere. Zh. Mat. Fiz. Anal. Geom. 16(3), 312–363 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  36. Musso, E., Nicolodi, L.: On the total CR twist of transversal curves in the 3-sphere, SIGMA Symmetry Integrability Geom. Methods Appl. 19 (2023), Paper No. 101, 36 pp

  37. Musso, E., Salis, F.: The Cauchy-Riemann strain functional for Legendrian curves in the 3-sphere. Ann. Mat. Pura Appl. (4) 199, 2395–2434 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  38. Pember, M.: Lie applicable surfaces. Comm. Anal. Geom. 28(6), 1407–1450 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  39. Pinkall, U.: Dupin hypersurfaces. Math. Ann. 270, 427–440 (1985)

    Article  MathSciNet  MATH  Google Scholar 

  40. Sato, H., Yamaguchi, K.: Lie contact manifolds, in Geometry of Manifolds (edited by K. Shiohama), 191–238. Perspect. Math., 8, Academic Press, Inc., Boston, MA, (1989)

  41. Sato, H., Yamaguchi, K.: Lie contact manifolds II. Math. Ann. 297(1), 33–57 (1993)

    Article  MathSciNet  MATH  Google Scholar 

  42. Ulrych, S.: Lie sphere geometry in nuclear scattering processes, J. Math. Anal. Appl. 491 (2020), no. 2, 124324, 11 pp

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Acknowledgements

The author gratefully acknowledges valuable input by Emilio Musso. This work was partially supported by PRIN 2017 and 2022 “Real and Complex Manifolds: Topology, Geometry and Holomorphic Dynamics" (protocolli 2017JZ2SW5-004 and 2022AP8HZ9-003); and by GNSAGA of INdAM. The author would like to thank the referee for his comments and suggestions.

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L.N. wrote and reviewed the manuscript.

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Correspondence to Lorenzo Nicolodi.

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In memory of Professor Lieven Vanhecke (1939-2023).

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Nicolodi, L. On a variational problem for curves in Lie sphere geometry. Ann Glob Anal Geom 68, 18 (2025). https://doi.org/10.1007/s10455-025-10021-4

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