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Foldings of G-trees

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Part of the book series: Mathematical Sciences Research Institute Publications ((MSRI,volume 19))

Abstract

The theory of group actions on trees is used to produce a proof of Grushko’s theorem, which extends to a theorem involving amalgamated free products; this mimics the author’s topological proof, but some new consequences are drawn. Theorems of Shenitzer and Swarup on amalgamations and HNN-extensions over cyclic subgroups are deduced as a consequence and somewhat generalized.

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References

  1. H. Kneser, Geschlossene Flächen in dreidimensionalen Mannigfaltigkeiten, Jahresb. der Deut. Math.-Verein. 38 (1929), 248–260.

    MATH  Google Scholar 

  2. I.A. Grusško, On generators of a free product of groups, Matem. Sbornik N. S. 8 (1940), 169–182.

    Google Scholar 

  3. F.W. Levi, On the number of generators of a free product, and a lemma of Alexander Kurosch, Indian Math.Soc. N. S. 5 (1941), 149–155.

    MathSciNet  MATH  Google Scholar 

  4. B.H. Neumann, On the number of generators of a free product, J. London Math. Soc. 18 (1943), 12–20.

    Article  MathSciNet  MATH  Google Scholar 

  5. A. Shenitzer, Decomposition of a group with a single defining relation into a free product, Proc. Amer. Math. Soc. 6 (1955), 273–279.

    Article  MathSciNet  MATH  Google Scholar 

  6. D.H. Wagner, On free products of groups, Trans. Amer. Math. Soc. 84 (1957), 352–378.

    Article  MathSciNet  MATH  Google Scholar 

  7. R.C. Lyndon, Grushko’s theorem, Proc. Amer. Math. Soc. 16 (1965), 822–826.

    MathSciNet  MATH  Google Scholar 

  8. J.R. Stallings, A topological proof of Grushko’s theorem on free products, Math. Z. 90 (1965), 1–8.

    Article  MathSciNet  MATH  Google Scholar 

  9. P.J. Higgins, Grushko’s theorem, J. Algebra 4 (1966), 365–372.

    Article  MathSciNet  MATH  Google Scholar 

  10. H. Zieschang, Ober die Nielsensche Kürzungsmethode in freien Produkten mit Amalgam, Inv. Math. 10 (1970), 4–37.

    Article  MathSciNet  MATH  Google Scholar 

  11. I.M. Chiswell, The Grushko-Neumann theorem, Proc. London Math. Soc. (3) 33 (1976), 385–400.

    Article  MathSciNet  MATH  Google Scholar 

  12. N. Smythe, A generalization of Grushko’s theorem to the mapping cylinder group,Notices Amer. Math. Soc. 23 (1976), A-419.

    Google Scholar 

  13. H. Bass, Some remarks on group actions on trees, Comm. Alg. 4 (1976), 1091–1126.

    Article  MathSciNet  MATH  Google Scholar 

  14. J.-P. Serre, “Arbres, Amalgames, SL 2, Astérisque, 1977.

    Google Scholar 

  15. G.P. Scott, Strong annulus and torus theorems and the enclosing property of characteristic submanifolds of 3-manifolds, Quart. J. Math. Oxford (2) 35 (1984), 485–506.

    Article  MATH  Google Scholar 

  16. G.A. Swarup, Decompositions of free groups, J. Pure and Appl. Alg. 40 (1986), 99–102.

    Article  MathSciNet  MATH  Google Scholar 

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© 1991 Springer-Verlag New York, Inc.

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Stallings, J.R. (1991). Foldings of G-trees. In: Alperin, R.C. (eds) Arboreal Group Theory. Mathematical Sciences Research Institute Publications, vol 19. Springer, New York, NY. https://doi.org/10.1007/978-1-4612-3142-4_14

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  • DOI: https://doi.org/10.1007/978-1-4612-3142-4_14

  • Publisher Name: Springer, New York, NY

  • Print ISBN: 978-1-4612-7811-5

  • Online ISBN: 978-1-4612-3142-4

  • eBook Packages: Springer Book Archive

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