Papers
Topics
Authors
Recent
AI Research Assistant
AI Research Assistant
Well-researched responses based on relevant abstracts and paper content.
Custom Instructions Pro
Preferences or requirements that you'd like Emergent Mind to consider when generating responses.
Gemini 2.5 Flash
Gemini 2.5 Flash 71 tok/s
Gemini 2.5 Pro 50 tok/s Pro
GPT-5 Medium 21 tok/s Pro
GPT-5 High 19 tok/s Pro
GPT-4o 91 tok/s Pro
Kimi K2 164 tok/s Pro
GPT OSS 120B 449 tok/s Pro
Claude Sonnet 4 36 tok/s Pro
2000 character limit reached

Relative hyperbolicity of free extensions of free groups (2307.09674v3)

Published 18 Jul 2023 in math.GR and math.GT

Abstract: We give necessary and sufficient conditions for a free-by-free group to be relatively hyperbolic with a cusp-preserving structure. Namely, if $\phi_1, \ldots , \phi_k $ is a collection of exponentially growing outer automorphisms with a common invariant \emph{subgroup system} such that any conjugacy class in the complement of this system grows exponentially under iteration by all $\phi_i$, then such a subgroup system can be used to construct a collection of peripheral subgroups relative to which, the extension of $\mathbb F$ by the free group generated by sufficiently high powers of $\phi_1, \ldots , \phi_k $, will be hyperbolic.

Definition Search Book Streamline Icon: https://streamlinehq.com
References (33)
  1. M. Bestvina and M. Feighn. A combination theorem for negatively curved groups. J. Differential Geom., 35(1):85–101, 1992.
  2. Laminations, trees, and irreducible automorphisms of free groups. Geom. Funct. Anal., 7(2):215–244, 1997.
  3. The Tits alternative for Out⁢(Fn)Outsubscript𝐹𝑛{\rm Out}(F_{n})roman_Out ( italic_F start_POSTSUBSCRIPT italic_n end_POSTSUBSCRIPT ). I. Dynamics of exponentially-growing automorphisms. Ann. of Math. (2), 151(2):517–623, 2000.
  4. Train tracks and automorphisms of free groups. Ann. of Math. (2), 135(1):1–51, 1992.
  5. B. H. Bowditch. Geometrical finiteness for hyperbolic groups. J. Funct. Anal., 113(2):245–317, 1993.
  6. B. H. Bowditch. Geometrical finiteness with variable negative curvature. Duke Math. J., 77(1):229–274, 1995.
  7. Brian H. Bowditch. The Cannon-Thurston map for punctured-surface groups. Math. Z., 255(1):35–76, 2007.
  8. B. H. Bowditch. Relatively hyperbolic groups. Internat. J. Algebra Comput., 22(3):1250016, 66, 2012.
  9. P. Brinkmann. Hyperbolic automorphisms of free groups. Geom. Funct. Anal., 10(5):1071–1089, 2000.
  10. Daryl Cooper. Automorphisms of free groups have finitely generated fixed point sets. J. Algebra, 111(2):453–456, 1987.
  11. François Dahmani. Les groupes relativement hyperboliques et leurs bords, volume 2003/13 of Prépublication de l’Institut de Recherche Mathématique Avancée [Prepublication of the Institute of Advanced Mathematical Research]. Université Louis Pasteur, Département de Mathématique, Institut de Recherche Mathématique Avancée, Strasbourg, 2003. Thèse, l’Université Louis Pasteur (Strasbourg I), Strasbourg, 2003.
  12. François Dahmani and Suraj Krishna M S. Relative hyperbolicity of hyperbolic-by-cyclic groups. Groups Geom. Dyn., 17(2):403–426, 2023.
  13. Relative hyperbolicity for automorphisms of free products and free groups. J. Topol. Anal., 14(1):55–92, 2022.
  14. Hyperbolic extensions of free groups. Geom. Topol., 22(1):517–570, 2018.
  15. B. Farb. Relatively hyperbolic groups. Geom. Funct. Anal., 8(5):810–840, 1998.
  16. The recognition theorem for Out⁢(Fn)Outsubscript𝐹𝑛{\rm Out}(F_{n})roman_Out ( italic_F start_POSTSUBSCRIPT italic_n end_POSTSUBSCRIPT ). Groups Geom. Dyn., 5(1):39–106, 2011.
  17. Pritam Ghosh. Limits of conjugacy classes under iterates of hyperbolic elements of Out⁢(𝔽)Out𝔽{\rm Out}(\mathbb{F})roman_Out ( blackboard_F ). Groups Geom. Dyn., 14(1):177–211, 2020.
  18. Pritam Ghosh. Relative hyperbolicity of free-by-cyclic extensions. Compos. Math., 159(1):153–183, 2023.
  19. Regluing graphs of free groups. Algebr. Geom. Topol., 22(4):1969–2006, 2022.
  20. M. Gromov. Hyperbolic groups. In Essays in group theory, volume 8 of Math. Sci. Res. Inst. Publ., pages 75–263. Springer, New York, 1987.
  21. Mark Hagen. A remark on thickness of free-by-cyclic groups. Illinois J. Math., 63(4):633–643, 2019.
  22. M. Handel and Lee Mosher. Subgroup classification in Out(Fnsubscript𝐹𝑛F_{n}italic_F start_POSTSUBSCRIPT italic_n end_POSTSUBSCRIPT). arXiv, 2009.
  23. The free splitting complex of a free group, II: Loxodromic outer automorphisms. Trans. Amer. Math. Soc., 372(6):4053–4105, 2019.
  24. Subgroup decomposition in Out⁢(Fn)Outsubscript𝐹𝑛{\rm Out}(F_{n})roman_Out ( italic_F start_POSTSUBSCRIPT italic_n end_POSTSUBSCRIPT ). Mem. Amer. Math. Soc., 264(1280):vii+276, 2020.
  25. G. Christopher Hruska. Relative hyperbolicity and relative quasiconvexity for countable groups. Algebr. Geom. Topol., 10(3):1807–1856, 2010.
  26. Lee Mosher. A hyperbolic-by-hyperbolic hyperbolic group. Proc. Amer. Math. Soc., 125(12):3447–3455, 1997.
  27. A combination theorem for strong relative hyperbolicity. Geom. Topol., 12(3):1777–1798, 2008.
  28. Algebraic ending laminations and quasiconvexity. Algebr. Geom. Topol., 18(4):1883–1916, 2018.
  29. A combination theorem for metric bundles. Geom. Funct. Anal., 22(6):1636–1707, 2012.
  30. Denis V. Osin. Relatively hyperbolic groups: intrinsic geometry, algebraic properties, and algorithmic problems. Mem. Amer. Math. Soc., 179(843):vi+100, 2006.
  31. Abhijit Pal. Relatively hyperbolic extensions of groups and Cannon-Thurston maps. Proc. Indian Acad. Sci. Math. Sci., 120(1):57–68, 2010.
  32. William P. Thurston. Hyperbolic Structures on 3-manifolds, II: Surface groups and 3-manifolds which fiber over the circle. Preprint, arXiv:math/9801045.
  33. Caglar Uyanik. Hyperbolic extensions of free groups from atoroidal ping-pong. Algebr. Geom. Topol., 19(3):1385–1411, 2019.
Citations (1)

Summary

We haven't generated a summary for this paper yet.

Lightbulb On Streamline Icon: https://streamlinehq.com

Continue Learning

We haven't generated follow-up questions for this paper yet.

List To Do Tasks Checklist Streamline Icon: https://streamlinehq.com

Collections

Sign up for free to add this paper to one or more collections.

X Twitter Logo Streamline Icon: https://streamlinehq.com

Tweets

This paper has been mentioned in 1 post and received 0 likes.