Abstract
We characterize the automorphism groups of circulant digraphs whose connection sets are relatively small, and of unit circulant digraphs. For each class, we either explicitly determine the automorphism group or we show that the graph is a “normal” circulant, so the automorphism group is contained in the normalizer of a cycle. Then we use these characterizations to prove results on the automorphisms of the endomorphism monoids of those digraphs. The paper ends with a list of open problems on graphs, number theory, groups and semigroups.
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M. E. Adams, S. Bulman-Fleming and M. Gould: Endomorphism properties of algebraic structures, in: Proceedings of the Tennessee Topology Conference (Nashville, TN, 1996), 1–17, World Sci. Publishing, River Edge, NJ, 1997.
R. Akhtar, T. Jackson-Henderson, R. Karpman, M. Boggess, I. Jiménez, A. Kinzel and D. Pritikin: On the unitary Cayley graph of a finite ring, Electron. J. Combin. 16 (2009), no. 1, Research Paper 117, 13.
B. Alspach and T. D. Parsons: Isomorphism of circulant graphs and digraphs, Discrete Math. 25 (1979), 97–108.
J. Araújo, E. Dobson and J. Konieczny: Automorphisms of endomorphism semigroups of re exive digraphs, Math. Nachr. 283 (2010), 939–964.
J. Araújo, V. H. Fernandes, M. Jesus, V. Maltcev and J. D. Mitchell: Automorphisms of partial endomorphism semigroups, Publicationes Mathematicae Debrecen 79 (1–2) (2011), 23–39.
J. Araújo and M. Kinyon: Inverse semigroups with idempotent-fixing automorphisms, Semigroup Forum 89 (2014), 469–474.
J. Araújo and J. Konieczny: Dense relations are determined by their endomorphism monoids, Semigroup Forum 70 (2005), 302–306.
J. Araújo and J. Konieczny: Automorphism groups of centralizers of idempotents, J. Algebra 269 (2003), 227–239.
J. Araújo and J. Konieczny: Automorphisms of the endomorphism monoids of relatively free bands, Proc. Edinb. Math. Soc. (2) 50 (2007), 1–21.
J. Araújo and J. Konieczny: A method of finding automorphism groups of endomorphism monoids of relational systems, Discrete Math. 307(13), (2007), 1609–1620.
J. Araújo and J. Konieczny: Automorphisms of endomorphism monoids of 1simple free algebras, Comm. Algebra 37 (2009), 83–94.
J. Araújo and J. Konieczny: General theorems on automorphisms of semigroups and their applications, Journal of the Australian Mathematical Society 87 (2009), 1–17.
L. Babai: Isomorphism problem for a class of point-symmetric structures, Acta Math. Acad. Sci. Hungar. 29 (1977), 329–336.
S. Bhoumik, E. Dobson and J. Morris: Asymptotic automorphism groups of circulant graphs and digraphs, Ars Math. Contemp., 7 (2014), 487–506.
P. J. Cameron, M. Giudici, G. A. Jones, W. M. Kantor, M. H. Klin, D. Marušič and L. A. Nowitz: Transitive permutation groups without semiregular subgroups, J. London Math. Soc. (2) 66 (2002), 325–333.
J. D. Dixon and B. Mortimer: Permutation groups, Graduate Texts in Mathematics, vol. 163, Springer-Verlag, New York, 1996.
E. Dobson and J. Morris: Toida’s conjecture is true, Electron. J. Combin. 9 (2002), Research Paper 35 (electronic).
E. Dobson and J. Morris: On automorphism groups of circulant digraphs of squarefree order, Discrete Math. 299 (2005), 79–98.
E. Dobson and J. Morris: Automorphism groups of wreath product digraphs, Electron. J. Combin. 16 (2009), Research Paper 17.
S. A. Evdokimov and I. N. Ponomarenko: Characterization of cyclotomic schemes and normal Schur rings over a cyclic group, St. Petersburg Math. J. 14 (2003), 189–221.
W. Klotz and T. Sander: Some properties of unitary Cayley graphs, Electron. J. Combin. 14 (2007), Research Paper 45 (electronic).
L. M. Gluskín: Semi-groups of isotone transformations Uspehi Mat. Nauk 16 (1961), 157–162, (Russian).
K. H. Leung and S. H. Man: On Schur rings over cyclic groups II, J. Algebra 183 (1996), 273–285.
K. H. Leung and S. H. Man: On Schur rings over cyclic groups, Israel J. Math. 106 (1998), 251–267.
I. Levi: Automorphisms of normal transformation semigroups, Proc. Edinburgh Math. Soc. (2) 28 (1985), 185–205.
I. Levi: Automorphisms of normal partial transformation semigroups, Glasgow Math. J. 29 (1987), 149–157.
I. Levi: On the inner automorphisms of finite transformation semigroups, Proc. Edinburgh Math. Soc. (2) 39 (1996), 27–30.
C. H. Li: On isomorphisms of connected Cayley graphs, Discrete Math. 178 (1998), 109–122.
C. H. Li: Permutation groups with a cyclic regular subgroup and arc transitive circulants, J. Algebraic Combin. 21 (2005), 131–136.
A. E. Liber: On symmetric generalized groups, Mat. Sbornik N. S. 33 (1953), 531–544 (Russian).
K. D. Magill: Semigroup structures for families of functions, I. Some homomorphism theorems, J. Austral. Math. Soc. 7 (1967), 81–94.
A. I. Mal’cev: Symmetric groupoids, Mat. Sbornik N. S. 31 (1952), 136–151 (Russian).
G. Mashevitzky, B. M. Schein and G. I. Zhitomirski: Automorphisms of the endomorphism semigroup of a free inverse semigroup, Comm. Alg. 34 (2006), 3569–3584.
J. D. P. Meldrum: ‘Wreath products of groups and semigroups,” Pitman Monographs and Surveys in Pure and Applied Mathematics, vol. 74, Longman, Harlow, 1995.
M. Muzychuk, M. Klin and R. Pöschel: The isomorphism problem for circulant graphs via Schur ring theory, Codes and association schemes (Piscataway, NJ, 1999), 241–264, DIMACS Ser. Discrete Math. Theoret. Comput. Sci., vol. 56, Amer. Math. Soc., Providence, RI, 2001.
J. Schreier: Über Abbildungen einer abstrakten Menge Auf ihre Teilmengen, Fund. Math. 28 (1936), 261–264.
R. P. Sullivan: Automorphisms of transformation semigroups, J. Australian Math. Soc. 20 (1975), part 1, 77–84.
È. G. šutov: Homomorphisms of the semigroup of all partial transformations, Izv. Vysš. Učebn. Zaved. Matematika 3 (1961), 177–184 (Russian).
J. S. V. Symons: Normal transformation semigroups, J. Austral. Math. Soc. Ser. A 22 (1976), 385–390.
W. T. Tutte: A family of cubical graphs, Proc. Cambridge Philos. Soc. 43 (1947), 459–474.
Ju. M. Važenin: The elementary definability and elementary characterizability of classes of re exive graphs, Izv. Vyss. Ucebn. Matematika 122 (1972), 3–11 (Russian).
H. Wielandt: Permutation groups through invariant relations and invariant functions, lectures given at The Ohio State University, Columbus, Ohio, 1969.
H. Wielandt:’ Mathematische Werke/Mathematical works. Vol. 1,” Walter de Gruyter & Co., Berlin, 1994.
M. Y. Xu: Automorphism groups and isomorphisms of Cayley digraphs, Discrete Math. 182 (1998), 309–319.
H. Yang and X. Yang: Automorphisms of partition order-decreasing transformation monoids, Semigroup Forum 85 (2012), 513–524.
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Araújo, J., Bentz, W., Dobson, E. et al. Automorphism Groups of Circulant Digraphs With Applications to Semigroup Theory. Combinatorica 38, 1–28 (2018). https://doi.org/10.1007/s00493-016-3403-0
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DOI: https://doi.org/10.1007/s00493-016-3403-0