Abstract
This paper considers the existence of nondiscrete embeddings Γ ↦ G, where Γ is an abstract limit group and G is topological group. Namely, it is shown that a locally compact group G that admits a nondiscrete nonabelian free subgroup F admits a nondiscrete copy of every nonabelian limit group L. In some cases, for instance if the F is of rank 2 and its closure in G is compact or semisimple algebraic, or if L is a surface group (as considered in [6]), L can be chosen with the same closure as F.
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References
M. Abert and Y. Glasner, Generic groups acting on regular trees, Trans. Amer. Math. Soc. 361 (2009), 3597–3610.
G. Baumslag, On generalised free products, Math. Z. 78 (1962), 423–438.
M. Bestvina and M. Feign, Notes on Sela’s work: limit groups and Makanin-Razborov diagrams, in Geometric and Cohomological Methods in Group Theory. Cambridge University Press, Cambridge, 2009, pp. 1–29.
E. Breuillard and T. Gelander, On dense free subgroups of Lie groups, J. Algebra 261 (2003), 448–467.
E. Breuillard and T. Gelander, A topological Tits alternative, Ann. of Math. (2) 166 (2007), 427–474.
E. Breuillard, T. Gelander, J. Souto and P. Storm, Dense embeddings of surface groups, Geom. Topol. 10 (2006), 1373–1389.
M. Bridson and A. Haefliger, Metric Spaces of Non-positive Curvature, Springer-Verlag, Berlin, 1999.
C. Champetier and V. Guirardel, Limit groups as limits of free groups, Israel J. Math. 146 (2005), 1–75.
L. Conlon, Differentiable Manifolds, second edition, Birkhäuser, Basel, 2001.
F. Dahmani, Combination of convergence groups, Geom. Topol. 7 (2003), 933–963.
J. D. Dixon, L. Pyber, A. Seress and A. Shalev, Residual properties of free groups and probabilistic methods, J. Reine Angew. Math. 556 (2003), 159–172.
J. Dixon, M. du Sautoy, A. Mann and D. Segal, Analytic pro-p Groups, London Math. Soc. Lect. Note Ser. 157, Cambridge Univ. Press, Cambridge, 1991.
T. Gelander, On deformations of F n in compact Lie groups, Israel J. Math. 167 (2008), 15–26.
T. Gelander and Y. Glasner, Countable primitive groups, Geom. Funct. Anal. 17 (2008), 1479–1523.
T. Gelander and Y. Minsky, The dynamics of Aut(F n) on the redundant part of the character variety, in preparation.
T. Gelander and A. Żuk, Dependence of Kazhdan constants on generating subsets, Israel J. Math. 129 (2002), 93–98.
V. M. Gluskov, The structure of locally compact groups and Hilbert’s fifth problem, Amer. Math. Soc., Transl. ser. 2 15 (1960), 55–93.
P. de la Harpe, Topics in Geometric Group Theory, Chicago Lectures in Mathematics, University of Chicago Press, Chicago, IL, 2000.
E. Hewitt and K. A. Ross, Abstract Harmonic Analysis, Vol. I: Structure of Topological Groups. Integration Theory, Group Representations, Academic Press, New York; Springer-Verlag, Berlin, 1963.
I. Kaplansky, Lie Algebras and Locally Compact Groups, University of Chicago Press, Chicago, IL, 1971.
M. Kuranishi, On everywhere dense embedding of free groups in Lie groups, Nagoya Math. J. 2 (1951), 63–71.
G. Margulis, Some remarks on invariant means, Monatsh. Math. 90 (1980), 233–235.
G. Margulis, Discrete Subgroups of Semisimple Lie Groups, Springer, Berlin, 1991.
D. Montgomery and L. Zippin, Topological Transformation Groups, Reprint of the 1955 original, Robert E. Krieger Publ. Co., Huntington, NY, 1974, xi+289 pp.
V. Platonov and A. Rapinchuk, Algebraic Groups and Number Theory, Academic Press, New York, 1994.
G. Prasad, Elementary proof of a theorem of Bruhat-Tits-Rousseau and of a theorem of Tits, Bull. Soc. Math. France 110 (1982), 197–202.
M. S. Raghunathan, Discrete Subgroups of Lie Groups, Springer, Berlin, 1972.
Z. Sela, Diophantine geometry over groups. I. Makanin-Razborov diagrams, Publ. Math. Inst. Hautes Études Sci. 93 (2001), 31–105.
D. Sullivan, For n > 3 there is only one finitely additive rotationally invariant measure on the n-sphere on all Lebesgue measurable sets, Bull. Amer. Math. Soc. 4 (1981), 121–123.
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T. Gelander acknowledges financial support from the European Community’s seventh Framework Programme (FP7/2007-2013)/ERC grant agreement 260508, and from the Israeli Science Foundation.
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Barlev, J., Gelander, T. Compactifications and algebraic completions of limit groups. JAMA 112, 261–287 (2010). https://doi.org/10.1007/s11854-010-0030-3
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DOI: https://doi.org/10.1007/s11854-010-0030-3