Abstract
We prove that for any act X over a finite semigroup S, the congruence lattice \({{\,\mathrm{Con}\,}}X\) embeds the lattice \({{\,\mathrm{Eq}\,}}M\) of all equivalences of an infinite set M if and only if X is infinite. Equivalently: for an act X over a finite semigroup S, the lattice \({{\,\mathrm{Con}\,}}X\) satisfies a non-trivial identity if and only if X is finite. Similar statements are proved for an act with zero over a completely 0-simple semigroup \({\mathcal {M}}^0(G,I,\Lambda ,P)\) where \(|G|,|I| <\infty \). We construct examples that show that the assumption \(|G|,|I| <\infty \) is essential.
Similar content being viewed by others
Data Availability Statement
No datasets were generated or analysed during the current study.
References
Avdeyev, A.Yu., Kozhuhov, I.B.: Acts over completely 0-simple semigroups. Acta Cybern. 14(4), 523–531 (2000)
Burris, S., Sankappanavar, H.P.: A Course in Universal Algebra. Graduate Texts in Mathematics, vol. 78. Springer, New York (1981)
Clifford, A.H., Preston, G.B.: The Algebraic Theory of Semigroups. American Mathematical Society, Providence (1958)
Cohn, P.M.: Universal Algebra. Springer, Dordrecht (1981)
Freeze, R., Je\(\tilde{\rm z}\)ek, J., Nation, J.B.: Free Lattices. Mathematical Surveys and Monographs, vol. 42. American Mathematical Society, Providence, RI (1995)
Grätzer, G.: Lattice Theory: Foundation. Birkhäuser, Basel (2011)
Jipsen, P., Rose, H.: Varieties of Lattices. Lecture Notes in Mathematics, vol. 1533. Springer, Berlin (1992)
Kearnes, K.A., Kiss, E.W.: The shape of congruence lattices. Mem. Am. Math. Soc. 222(1046) (2013)
Khaliullina, A.R.: Modularity conditions of the congruence lattice of acts over right or left zero semigroups. Far East. Math. J. 15(1), 102–120 (2015) (in Russian)
Kilp, M., Knauer, U., Mikhalev, A.V.: Monoids, Acts and Categories. Walter de Gruyter, Berlin (2000)
Kozhukhov, I.B., Reshetnikov, A.V.: Algebras whose equivalence relations are congruences. J. Math. Sci. 177(886) 886–907 (2011)
Oehmke, R.H.: Right congruences and semisimplicity for Rees matrix semigroups. Pac. J. Math. 54(2), 143–164 (1974)
Ptahov, D.O., Stepanova, A.A.: Congruence lattice of S-acts. Far East. Math. J. 13(1), 107–115 (2013) (in Russian)
Sachs, D.: Identities in finite partition lattices. Proc. Am. Math. Soc. 12, 944–945 (1961)
Acknowledgements
The authors would like to thank the referee for his valuable comments and suggestions which allowed them to eliminate defects and to correct one proof.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Presented by E. W. Kiss.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Research supported by a grant of the Center Fund. Appl. Math. of Lomonosov MSU.
Rights and permissions
About this article
Cite this article
Kozhuhov, I.B., Pryanichnikov, A.M. Acts with identities in the congruence lattice. Algebra Univers. 83, 16 (2022). https://doi.org/10.1007/s00012-022-00773-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00012-022-00773-6