Abstract
For an arbitrary set X (finite or infinite), denote by T(X) the semigroup of full transformations on X. For α∈T(X), let C(α)={β∈T(X):αβ=βα} be the centralizer of α in T(X). The aim of this paper is to characterize the elements of C(α). The characterization is obtained by decomposing α as a join of connected partial transformations on X and analyzing the homomorphisms of the directed graphs representing the connected transformations. The paper closes with a number of open problems and suggestions of future investigations.
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André, J.M., Araújo, J., Konieczny, J.: Regular centralizers of idempotent transformations. Semigroup Forum 82, 307–318 (2011)
Araújo, J., Dobson, E., Konieczny, J.: Automorphisms of endomorphism semigroups of reflexive digraphs. Math. Nachr. 283, 939–964 (2010)
Araújo, J., Kinyon, M., Konieczny, J.: Minimal paths in the commuting graphs of semigroups. Eur. J. Comb. 32, 178–197 (2011)
Araújo, J., Konieczny, J.: Automorphism groups of centralizers of idempotents. J. Algebra 269, 227–239 (2003)
Araújo, J., Konieczny, J.: Semigroups of transformations preserving an equivalence relation and a cross-section. Commun. Algebra 32, 1917–1935 (2004)
Araújo, J., Konieczny, J.: A method of finding automorphism groups of endomorphism monoids of relational systems. Discrete Math. 307, 1609–1620 (2007)
Araújo, J., Konieczny, J.: General theorems on automorphisms of semigroups and their applications. J. Aust. Math. Soc. 87, 1–17 (2009)
Araújo, J., Konieczny, J.: Directed Graphs of Inner Translations of Semigroups to appear
Araújo, J., Mitchell, J.: Relative ranks in the monoid of endomorphisms of an independence algebra. Monatshefte Math. 151, 1–10 (2007)
Bates, C., Bundy, D., Perkins, S., Rowley, P.: Commuting involution graphs for symmetric groups. J. Algebra 266, 133–153 (2003)
East, J., Mitchell, J.D., Péresse, Y.: Maximal subsemigroups of the semigroup of all functions on an infinite set. To appear
Hell, P., Nešetřil, J.: Graphs and Homomorphisms. Oxford University Press, New York (2004)
Higgins, P.M.: Digraphs and the semigroup of all functions on a finite set. Glasg. Math. J. 30, 41–57 (1988)
Howie, J.M.: The subsemigroup generated by the idempotents of a full transformation semigroup. J. Lond. Math. Soc. 41, 707–716 (1966)
Howie, J.M.: Fundamentals of Semigroup Theory. Oxford Science Publications, Oxford (1995)
Howie, J.M., Ruškuc, N., Higgins, P.M.: On relative ranks of full transformation semigroups. Commun. Algebra 26, 733–748 (1998)
Iranmanesh, A., Jafarzadeh, A.: On the commuting graph associated with the symmetric and alternating groups. J. Algebra Appl. 7, 129–146 (2008)
Jakubíková, D.: Systems of unary algebras with common endomorphisms. I, II. Czechoslov. Math. J. 29(104), 406–420 (1979). 421–429
Kolmykov, V.A.: On the commutativity relation in a symmetric semigroup. Sib. Math. J. 45, 931–934 (2004)
Kolmykov, V.A.: Endomorphisms of functional graphs. Discrete Math. Appl. 16, 423–427 (2006)
Kolmykov, V.A.: On commuting mappings. Math. Notes 86, 357–360 (2009)
Konieczny, J.: Green’s relations and regularity in centralizers of permutations. Glasg. Math. J. 41, 45–57 (1999)
Konieczny, J.: Semigroups of transformations commuting with idempotents. Algebra Colloq. 9, 121–134 (2002)
Konieczny, J.: Semigroups of transformations commuting with injective nilpotents. Commun. Algebra 32, 1951–1969 (2004)
Konieczny, J.: Centralizers in the semigroup of injective transformations on an infinite set. Bull. Aust. Math. Soc. 82, 305–321 (2010)
Konieczny, J.: Infinite injective transformations whose centralizers have simple structure. Cent. Eur. J. Math. 9, 23–35 (2011)
Konieczny, J., Lipscomb, S.: Centralizers in the semigroup of partial transformations. Math. Jpn. 48, 367–376 (1998)
Lipscomb, S.L.: The structure of the centralizer of a permutation. Semigroup Forum 37, 301–312 (1988)
Lipscomb, S., Konieczny, J.: Centralizers of permutations in the partial transformation semigroup. Pure Math. Appl. 6, 349–354 (1995)
Liskovec, V.A., Feĭnberg, V.Z.: On the permutability of mappings. Dokl. Akad. Nauk BSSR 7, 366–369 (1963). (Russian)
Mitchell, J.D., Morayne, M.P., Péresse, Y., Quick, M.: Generating transformation semigroups using endomorphisms of preorders, graphs, and tolerances. Ann. Pure Appl. Log. 161, 1471–1485 (2010)
Mitchell, J.D., Péresse, Y.: Generating countable sets of surjective functions. Fundam. Math. 213, 67–93 (2011)
Novotný, M.: O jednom problému z teorie zobrazení. Publ. Fac. Sci. Univ. Massaryk 344, 53–64 (1953). (Czech)
Novotný, M.: Über abbildungen von mengen. Pac. J. Math. 13, 1359–1369 (1963). (German)
Skornjakov, L.A.: Unary algebras with regular endomorphism monoids. Acta Sci. Math. (Szeged) 40, 375–381 (1978)
Suzuki, M.: Group Theory I. Springer, New York (1982)
Szechtman, F.: On the automorphism group of the centralizer of an idempotent in the full transformation monoid. Semigroup Forum 70, 238–242 (2005)
Weaver, M.W.: On the commutativity of a correspondence and a permutation. Pac. J. Math. 10, 705–711 (1960)
Zupnik, D.: Cayley functions. Semigroup Forum 3, 349–358 (1972)
Acknowledgements
The first author was partially supported by FCT through the following projects: PEst-OE/MAT/UI1043/2011, Strategic Project of Centro de Álgebra da Universidade de Lisboa; and PTDC/MAT/101993/2008, Project Computations in groups and semigroups.
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Communicated by Mikhail Volkov.
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Araújo, J., Konieczny, J. Centralizers in the Full Transformation Semigroup. Semigroup Forum 86, 1–31 (2013). https://doi.org/10.1007/s00233-012-9424-0
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DOI: https://doi.org/10.1007/s00233-012-9424-0