Skip to main content
Log in

Free quotients and the first betti number of some hyperbolic manifolds

  • Published:
Transformation Groups Aims and scope Submit manuscript

Abstract

In this note we present a very simple method of proving that some hyperbolic manifoldsM have finite sheeted covers with positive first Betti number. The method applies to the standard arithmetic subgroups ofSO(n,1) (a case which was proved previously by Millson [Mi]), to the non-arithmetic lattices inSO(n,1) constructed by Gromov and Piatetski-Shapiro [GPS] and to groups generated by reflections. In all these cases we actually show that Γ=π1(M) has a finite index subgroup which is mapped onto a nonabelian free group.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • [Bo] A. Borel,Cohomologie de sous-groupes discrètes et représentations de groupes semi-simple, Astérisque32–33 (1976), 73–112.

    MathSciNet  Google Scholar 

  • [GPS] M. Gromov, I. Piatetski-Shapiro,Nonarithmetic groups in Lobachevsky spaces. Publ. Math. IHES66 (1988), 93–103.

    MATH  MathSciNet  Google Scholar 

  • [GS] F. Grunewald, J. Schwermer,Free non-abelian quotients of SL 2 over orders of imaginary quadratic number fields, J. Alg.6 (1981), 298–304.

    Article  MathSciNet  Google Scholar 

  • [H1] J. Hempel,Orientation reversing involutions and the first Betti number for finite coverings of 3-manifolds, Invent. Math.67 (1982), 133–142.

    Article  MATH  MathSciNet  Google Scholar 

  • [H2] J. Hempel,Residual finiteness for 3-manifolds, in: Combinatorial Group Theory and Topology (ed: S. M. Gersten and J. R. Stallings). Annals of Math. Studies, Princeton University Press111 (1987), 379–396.

  • [Ko] S. Kojima,Finite covers of 3-manifolds containing essential surfaces of Euler characteristic zero, Proc. AMS101 (1987), 743–747.

    Article  MATH  MathSciNet  Google Scholar 

  • [LN] D. D. Long, G. A. Niblo,Subgroup separability and 3-manifold proups, Math. Z.207 (1991), 209–215.

    Article  MATH  MathSciNet  Google Scholar 

  • [Lu1] A. Lubotzky,Free quotients and the congruence kernel of SL 2 J. Alg.77 (1982), 411–418.

    Article  MATH  MathSciNet  Google Scholar 

  • [Lu2] A. Lubotzky,Subgroup growth and congruence subgroups, Invent. Math.119 (1995), 267–295.

    Article  MATH  MathSciNet  Google Scholar 

  • [Lu3] A. Lubotzky,Eigenvalues of the Laplacian, the first Betti number and the congruence subgroup problem, to appear in Ann. Math.,

  • [Ma] G. A. Margulis,Discrete subgroups of Semisimple Lie Groups Springer-Verlag, Heidelberg, 1991.

    MATH  Google Scholar 

  • [MS] G. A. Margulis and G. A. Soifer,Maximal subgroups of infinite indices in finitely generated linear groups, J. Alg.69 (1981), 1–23.

    Article  MATH  MathSciNet  Google Scholar 

  • [Mi] J. Millson,On the first Betti number of a constant negatively curved manifold, Ann. Math.104 (1976), 235–247.

    Article  MathSciNet  Google Scholar 

  • [Ra] M. S. Raghunathan,The first Betti number of compact locally symmetric spaces, in: Current Trends in Mathematics and Physics-A Tribute to Harish-Chandra (ed: S. D. Adhikari) Nrosa Publishing House, New-Delhi (1995), 116–137.

    Google Scholar 

  • [Se1] J.-P. Serre,Le problème de groupes de congruence pour SL 2, Ann. Math.92 (1970), 489–527.

    Article  MathSciNet  Google Scholar 

  • [Se2] J.-P. Serre,Trees, Springer-Verlag, Heidelberg, 1980.

    MATH  Google Scholar 

  • [T] W. P. Thurston,Three dimensional manifolds, Kleinian groups and hyperbolic geometry, Bull. AMS6 (1982), 357–381.

    MATH  MathSciNet  Google Scholar 

  • [VS] E. B. Vinberg, O. V. Shvartsman,Discrete groups of motions of spaces of constant curvature, in: Encyclopedia of Mathematical Sciences: Geometry II (ed: E. B. Vinberg) Springer-Verlag, Berlin, Heidelberg, and New-York29 (1993), 139–248.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lubotzky, A. Free quotients and the first betti number of some hyperbolic manifolds. Transformation Groups 1, 71–82 (1996). https://doi.org/10.1007/BF02587736

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02587736

Keywords

Navigation