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On Suborbital Graphs for the Extended Modular Group \({\hat{\Gamma}}\)

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In this paper, we show that the extended modular group \({\hat{\Gamma}}\) acts on \({\hat{\mathbb{Q}}}\) transitively and imprimitively. Then the number of orbits of \({\hat{\Gamma} _{0}(N)}\) on \({\hat{\mathbb{Q}}}\) is calculated and compared with the number of orbits of \({\Gamma _{0}(N)}\) on \({\hat{\mathbb{Q}}}\). Especially, we obtain the graphs \({\hat{G}_{u, N}}\) of \({\hat{\Gamma}_{0}(N)}\) on \({\hat{\mathbb{Q}}}\), for each \({N\in\mathbb{N}}\) and each unit \({u \in U_{N} }\), then we determine the suborbital graph \({\hat{F}_{u,N}}\). We also give the edge conditions in \({\hat{G}_{u, N}}\) and the necessary and sufficient conditions for a circuit to be triangle in \({\hat{F}_{u, N}.}\)

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References

  1. Akbaş M.: On suborbital graphs for the modular group. Bull. London Math. Soc. 33(6), 647–652 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  2. Akbaş, M.: The Normalizer of Modular subgroups. Ph.D. Thesis, University of Southampton, (1989)

  3. Akbaş M., Başkan T.: Suborbital Graphs for the Normalizer of \({\Gamma _{0}(N)}\). Turkish J. Math. 20(3), 379–387 (1996)

    MathSciNet  MATH  Google Scholar 

  4. Biggs, N.L., White, A.T.: Permutation groups and combinatorial structures. London Math. Soc. Lecture Note Ser. 33, CUP, Cambridge (1979)

  5. Guler B.O., Besenk M., Deger A.H., Kader S.: Elliptic elements and circuits in suborbital graphs. Hacet. J. Math. Stat. 40(2), 203–210 (2011)

    MathSciNet  Google Scholar 

  6. Jones G.A., Singerman D., Wicks K.: The modular group and generalized farey graphs. London Math. Soc. Lecture Note Ser. 160, 316–338 (1991)

    MathSciNet  Google Scholar 

  7. Kader S., Guler B.O., Deger A.H.: Suborbital graphs for a special subgroup of the normalizer. IJST. Trans A. 34(A4), 305–312 (2010)

    MathSciNet  Google Scholar 

  8. Kulkarni R.S.: An arithmetic-geometric method in the study of the subgroups of the modular group. Am. J. Math. 113(6), 1053–1133 (1991)

    Article  MATH  Google Scholar 

  9. Neumann, P.M.: Finite permutation groups, edge-coloured graphs and matrices, topics. In: Curran, M.P.J. (ed.) Group Theory and Computation. Academic Press, London, New York, San Fransisco, (1977)

  10. Sims C.C.: Graphs and finite permutation groups. Math. Z. 95, 76–86 (1967)

    Article  MathSciNet  MATH  Google Scholar 

  11. Tsuzuku T.: Finite Groups and Finite Geometries. Cambridge University Press, Cambridge (1982)

    MATH  Google Scholar 

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Correspondence to Bahadır Özgür Güler.

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Kader, S., Güler, B.Ö. On Suborbital Graphs for the Extended Modular Group \({\hat{\Gamma}}\) . Graphs and Combinatorics 29, 1813–1825 (2013). https://doi.org/10.1007/s00373-012-1226-3

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  • DOI: https://doi.org/10.1007/s00373-012-1226-3

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