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On the displacement of generators of free Fuchsian groups

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Abstract

We prove an inequality that must be satisfied by displacement of generators of free Fuchsian groups, which is the two-dimensional version of the \(\log (2k-1)\) Theorem for Kleinian groups due to Anderson et al. (J Differ Geom 44:738–782, 1996). As applications, we obtain quantitative results on the geometry of hyperbolic surfaces such as the two-dimensional Margulis constant and lengths of a pair of based loops, which improves a result of Buser’s.

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References

  1. Anderson, J.W., Canary, R.D., Culler, M., Shalen, P.B.: Free Kleinian groups and volumes of hyperbolic $3$-manifolds. J. Differ. Geom. 44, 738–782 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  2. Benedetti, R., Petronio, C.: Lectures on Hyperbolic Geometry. Universitext. Springer, Berlin (1992)

    Book  MATH  Google Scholar 

  3. Bers, L.: Nielsen extensions of Riemann surfaces. Ann. Acad. Sci. Fenn. Ser. AI Math. 2, 29–34 (1976)

    Article  MathSciNet  MATH  Google Scholar 

  4. Buser, P.: The collar theorem and examples. Manuscr. Math. 25, 349–357 (1978)

    Article  MathSciNet  MATH  Google Scholar 

  5. Culler, M., Shalen, P.B.: Paradoxical decompositions, $2$-generator Kleinian groups, and volumes of hyperbolic $3$-manifolds. J. AMS 5, 231–288 (1992)

    MathSciNet  MATH  Google Scholar 

  6. Fortier Bourque, M.: The converse of the Schwarz lemma is false. Ann. Acad. Sci. Fenn. Math. 41, 235–241 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  7. Halpern, N.: Some remarks on Nielsen extensions of Riemann surfaces. Mich. Math. J. 30, 65–68 (1983)

    Article  MathSciNet  MATH  Google Scholar 

  8. Yamada, A.: On Marden’s universal constant of Fuchsian groups. Kodai Math. J. 4(2), 266–277 (1981)

    Article  MathSciNet  MATH  Google Scholar 

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Acknowledgements

I would like to thank Peter Shalen for his invaluable advice, gracious support and encouragement throughout this project. I thank David Dumas for pointing out the Proof of Lemma 4.4, Danny Calegari for helpful conversations and Yong Hou for commenting on the draft.

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Correspondence to Yan Mary He.

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He, Y.M. On the displacement of generators of free Fuchsian groups. Geom Dedicata 200, 255–264 (2019). https://doi.org/10.1007/s10711-018-0369-7

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  • DOI: https://doi.org/10.1007/s10711-018-0369-7

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