## Regular Cayley maps for cyclic groups

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- by Marston D.E. Conder and Thomas W. Tucker PDF
- Trans. Amer. Math. Soc.
**366**(2014), 3585-3609 Request permission

## Abstract:

An orientably-regular map $M$ is a 2-cell embedding of a connected graph in a closed, orientable surface, with the property that the group $\mathrm {Aut}^\textrm {o}M$ of all orientation-preserving automorphisms acts transitively on the arcs of $M$. If $\mathrm {Aut}^\textrm {o}M$ contains a subgroup $A$ that acts regularly on the vertex set, then $M$ is called a regular Cayley map for $A$. In this paper, we answer a question of recent interest by providing a complete classification of the regular Cayley maps for the cyclic group $C_n$, for every possible order $n$. This is the first such classification for any infinite family of groups. The approach used is entirely algebraic and does not involve skew morphisms (but leads to a classification of all skew morphisms which have an orbit that is closed under inverses and generates the group). A key step is the use of a generalisation by Conder and Isaacs (2004) of Ito’s theorem on group factorisations, to help determine the isomorphism type of $\mathrm {Aut}^\textrm {o}M$. This group is shown to be a cyclic extension of a cyclic or dihedral group, dependent on $n$ and a single parameter $r$, which is a unit modulo $n$ that satisfies technical number-theoretic conditions. For each $n$, we enumerate all such $r$, and then in terms of $r$, we find the valence and covalence of the map, and determine whether or not the map is reflexible, and whether it has a representation as a balanced, anti-balanced or $t$-balanced regular Cayley map.## References

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## Additional Information

**Marston D.E. Conder**- Affiliation: Department of Mathematics, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
- MR Author ID: 50940
- ORCID: 0000-0002-0256-6978
**Thomas W. Tucker**- Affiliation: Department of Mathematics, Colgate University, Hamilton, New York 13346
- MR Author ID: 175090
- ORCID: 0000-0002-7868-6925
- Received by editor(s): March 2, 2011
- Received by editor(s) in revised form: August 9, 2012
- Published electronically: March 3, 2014
- © Copyright 2014
American Mathematical Society

The copyright for this article reverts to public domain 28 years after publication. - Journal: Trans. Amer. Math. Soc.
**366**(2014), 3585-3609 - MSC (2010): Primary 05E18; Secondary 05C10, 20B25, 57M15
- DOI: https://doi.org/10.1090/S0002-9947-2014-05933-3
- MathSciNet review: 3192608