Abstract
The normalizer \(\varGamma _B(N)\) of \(\varGamma _0(N)\) in \(PSL(2,{\mathbb {R}})\) is the triangle group \((2,3,\infty )\) for \(N=2^\alpha 3^\beta \) where \(\alpha =0,2,4,6\); \(\beta =0,2\). In this paper we examine relationship between the normalizer and the regular maps for these values. We define a family of subgroups of the normalizer and then we study maps with triangular faces using these subgroups and calculating the associated arithmetic structure.





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Acknowledgements
The authors would like to thank the anonymous reviewers for their helpful and constructive comments that greatly contributed to improving the final version of the paper. They would also like to thank the Editors for their generous comments and support during the review process.Finally, the first and second authors would like to thank TUBITAK (The Scientific and Technological Research Council of Turkey) for their financial supports during their doctorate studies.
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Yazıcı Gözütok, N., Gözütok, U. & Güler, B.Ö. Maps Corresponding to the Subgroups \(\varGamma _0(N)\) of the Modular Group. Graphs and Combinatorics 35, 1695–1705 (2019). https://doi.org/10.1007/s00373-019-02080-9
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DOI: https://doi.org/10.1007/s00373-019-02080-9