Abstract
Mal\('\)cev described the congruences of the monoid \(\mathcal {T}_n\) of all full transformations on a finite set \(X_n=\{1, \dots ,n\}\). Since then, congruences have been characterized in various other monoids of (partial) transformations on \(X_n\), such as the symmetric inverse monoid \(\mathcal {I}_n\) of all injective partial transformations, or the monoid \(\mathcal {PT}_n\) of all partial transformations. The first aim of this paper is to describe the congruences of the direct products \(Q_m\times P_n\), where Q and P belong to \(\{\mathcal {T}, \mathcal {PT},\mathcal {I}\}\). Mal\('\)cev also provided a similar description of the congruences on the multiplicative monoid \(F_n\) of all \(n\times n\) matrices with entries in a field F; our second aim is to provide a description of the principal congruences of \(F_m \times F_n\). The paper finishes with some comments on the congruences of products of more than two transformation semigroups, and on a number of related open problems.
Similar content being viewed by others
References
Ahmed, C., Martin, P., Mazorchuk, V.: On the number of principal ideals in d-tonal partition monoids. arXiv:1503.06718
André, J., Araújo, J., Cameron, P.J.: The classification of partition homogeneous groups with applications to semigroup theory. J. Algebra 452, 288–310 (2016)
André, J.M., Araújo, J., Konieczny, J.: Regular centralizers of idempotent transformations. Semigroup Forum 82(2), 307–318 (2011)
Araújo, J., Bentz, W., Konieczny, J.: The largest subsemilattices of the semigroup of endomorphisms of an independence algebra. Linear Algebra Appl. 458, 50–79 (2014)
Araújo, J., Bentz, W., Cameron, P.J., Royle, G., Schaefer, A.: Primitive groups and synchronization. Proc. Lond. Math. Soc. 113, 829–867 (2016)
Araújo, J., Bentz, W., Mitchell, J.D., Schneider, C.: The rank of the semigroup of transformations stabilising a partition of a finite set. Math. Proc. Camb. Philos. Soc. 159(2), 339–353 (2015)
Araújo, J., Bentz, W., Dobson, E., Konieczny, J., Morris, J.: Automorphism groups of circulant digraphs with applications to semigroup theory. Combinatorica 38, 1–28 (2017)
Araújo, J., Cameron, P.J.: Primitive groups synchronize non-uniform maps of extreme ranks. J. Comb. Theory Ser. B 106, 98–114 (2014)
Araújo, J., Cameron, P.J.: Two generalizations of homogeneity in groups with applications to regular semigroups. Trans. Am. Math. Soc. 368, 1159–1188 (2016)
Araújo, J., Cameron, P.J., Mitchell, J.D., Neuhoffer, M.: The classification of normalizing groups. J. Algebra 373, 481–490 (2013)
Araújo, J., Cameron, P.J., Steinberg, B.: Between primitive and 2-transitive: synchronization and its friends. Eur. Math. Soci. Surv. Math. Sci. 4(2), 101–184 (2017)
Araújo, J., Fountain, J.: The origins of independence algebras. Semigroups Lang. 54–67 (2004)
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.: Centralizers in the full transformation semigroup. Semigroup Forum 86, 1–31 (2013)
Araújo, J., Silva, F.C.: Semigroups of linear endomorphisms closed under conjugation. Commun. Algebra 28(8), 3679–3689 (2000)
Araújo, J., Wehrung, F.: Embedding properties of endomorphism semigroups. Fundam. Math. 202, 125–146 (2009)
Cameron, P.J., Szabó, C.: Independence algebras. J. Lond. Math. Soc. 61, 321–334 (2000)
East, J.: Generators and relations for partition monoids and algebras. J. Algebra 339, 1–26 (2011)
East, J.: On the singular part of the partition monoid. Int. J. Algebra Comput. 21(1–2), 147–178 (2011)
Dolinka, I., East, J., Evangelou, A., FitzGerald, D., Ham, N., Hyde, J., Loughlin, N.: Enumeration of idempotents in diagram semigroups and algebras. J. Comb. Theory Ser. A 131, 119–152 (2015)
FitzGerald, D.G., Lau, K.W.: On the partition monoid and some related semigroups. Bull. Aust. Math. Soc. 83(2), 273–288 (2011)
Fountain, J., Gould, V.: Relatively free algebras with weak exchange properties. J. Aust. Math. Soc. 75, 355–384 (2003)
Fountain, J., Gould, V.: Endomorphisms of relatively free algebras with weak exchange properties. Algebra Univ. 51, 257–285 (2004)
Ganyushkin, O., Mazorchuk, V.: Classical Finite Transformation Semigroups. An Introduction. Algebra and Applications, vol. 9. Springer, London (2009)
Gould, V.: Independence algebras. Algebra Univ. 33, 294–318 (1995)
Howie, J.M.: Fundamentals of Semigroup Theory, London Mathematical Society Monographs. New Series, vol. 12. The Clarendon Press, New York (1995)
Kudryavtseva, A., Mazorchuk, V.: Square matrices as a semigroup. http://www2.math.uu.se/ research/pub/Mazorchuk9.pdf, July 6 (2015)
Levi, I.: Automorphisms of normal transformation semigroups. Proc. Edinb. Math. Soc. 28, 185–205 (1985)
Levi, I.: Automorphisms of normal partial transformation semigroups. Glasg. Math. J. 29, 149–157 (1987)
Levi, I.: Congruences on normal transformation semigroups. Math. Jpn. 52(2), 247–261 (2000)
Levi, I., McAlister, D.B., McFadden, R.B.: Groups associated with finite transformation semigroups. Semigroup Forum 61(3), 453–467 (2000)
Liber, A.: On symmetric generalized groups. Mat. Sb. N.S. 33(75), 531–544 (1953)
Mal’cev, A.: Symmetric groupoids. Mat. Sb. N. S. 31(73), 136–151 (1952)
Mal’cev, A.: Multiplicative congruences of matrices. Dokl. Akad. N. S. 90, 333–335 (1953)
McAlister, Donald B.: Semigroups generated by a group and an idempotent. Commun. Algebra 26(2), 515–547 (1998)
Neumann, P.M.: Primitive permutation groups and their section-regular partitions. Mich. Math. J. 58, 309–322 (2009)
Schein, B., Teclezghi, B.: Endomorphisms of finite full transformation semigroups. Proc. Am. Math. Soc. 126(9), 2579–2587 (1998)
Šutov, E.: Homomorphisms of the semigroup of all partial transformations. Izv. Vysshikh Uchebnykh Zaved. Mat. 22(3), 177–184 (1961)
Symons, J.S.V.: Normal transformation semigroups. J. Aust. Math. Soc. Ser. A 22(4), 385–390 (1976)
Urbanik, K.: A representation theorem for \(v^*\)-algebras. Fundam. Math. 52, 291–317 (1963)
Acknowledgements
The authors were supported by FCT (Portugal) through project UID/MULTI/04621/2013 of CEMAT-Ciências. Wolfram Bentz has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. PCOFUND-GA-2009-246542 and from the Foundation for Science and Technology of Portugal under PCOFUND-GA-2009-246542 and SFRH/BCC/52684/2014. The authors wish to thank the referee for his or her helpful remarks.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Mikhail Volkov.
Rights and permissions
About this article
Cite this article
Araújo, J., Bentz, W. & Gomes, G.M.S. Congruences on direct products of transformation and matrix monoids. Semigroup Forum 97, 384–416 (2018). https://doi.org/10.1007/s00233-018-9931-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00233-018-9931-8