Abstract
Let λ and κ be cardinal numbers such that κ is infinite and either 2 ≤ λ ≤ κ, or λ = 2κ. We prove that there exists a lattice L with exactly λ many congruences, 2κ many ideals, but only κ many filters. Furthermore, if λ ≥ 2 is an integer of the form 2m · 3n, then we can choose L to be a modular lattice generating one of the minimal modular nondistributive congruence varieties described by Ralph Freese in 1976, and this L is even relatively complemented for λ = 2. Related to some earlier results of George Grätzer and the first author, we also prove that if P is a bounded ordered set (in other words, a bounded poset) with at least two elements, G is a group, and κ is an infinite cardinal such that κ ≤ |P| and κ ≤ |G|, then there exists a lattice L of cardinality κ such that (i) the principal congruences of L form an ordered set isomorphic to P, (ii) the automorphism group of L is isomorphic to G, (iii) L has 2κ many ideals, but (iv) L has only κ many filters.
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J. E. Avery, J. Y. Moyen, P. Růžička and J. G. Simonsen, Chains, antichains, and complements in infinite partition lattices, ar**v (2015), ar**v: 1501.05284.
V. A. Baranski, Independence of lattices of congruences and groups of automorphisms of lattices, Iv. Vyssh. Uchebn. Zaved. Mat., 76 (1984), 12–17 (in Russian); translation in Soviet Math. (Iz. VUZ), 28 (1984), 12–19.
S. Burris and H. P. Sankappanavar, A Course in Universal Algebra, Graduate Texts in Mathematics, vol. 78, Springer-Verlag, New York-Berlin, 1981.
P. Crawley, Lattices whose congruences form a boolean algebra, Pacific J. Math., 10 (1960), 787–795.
G. Czédli, On the 2-distributivity of sublattice lattices, Acta Math. Acad. Sci. Hungar., 36 (1980), 49–55.
G. Czédli, Representing a monotone map by principal lattice congruences, Acta Math. Hungar., 147 (2015), 12–18.
G. Czédli, The ordered set of principal congruences of a countable lattice, Algebra Universalis, 75 (2016), 351–380.
G. Czédli, An independence theorem for ordered sets of principal congruences and automorphism groups of bounded lattices, Acta Sci. Math. (Szeged), 82 (2016), 3–18.
G. Czédli, Representing some families of monotone maps by principal lattice congruences, Algebra Universalis, 77 (2017), 51–77; doi: 10.1007/s00012–016–0419–7.
G. Czédli, Cometic functors and representing order-preserving maps by principal lattice congruences, Algebra Universalis, 79, (2018), 1–32; doi: 10.1007/s00012–018–0545–5.
R. Freese, Minimal modular congruence varieties, Amer. Math. Soc. Notices, 23 (1976), #76T-A181.
R. Freese, C. Herrmann and A. P. Huhn, On some identities valid in modular congruence varieties, Algebra Universalis, 12 (1981), 322–334.
G. Grätzer, The Congruences of a Finite Lattice, A Proof-by-Picture Approach, second edition, Birkhäuser, 2016.
G. Grätzer, Lattice Theory: Foundation, Birkhäuser, Basel, 2011.
G. Grätzer, The order of principal congruences of a bounded lattice, Algebra Universalis, 70 (2013), 95–105.
G. Grätzer, Homomorphisms and principal congruences of bounded lattices, I. Isotone maps of principal congruences, Acta Sci. Math. (Szeged), 82 (2016), 353–360.
G. Grätzer, Homomorphisms and principal congruences of bounded lattices, II. Sketching the proof for sublattices, Algebra Universalis, 78 (2017), 291–295; doi: 10. 1007/s00012–017–0461–0.
G. Grätzer, Homomorphisms and principal congruences of bounded lattices, III. The Independence Theorem, Algebra Universalis, 78 (2017), 297–301; doi: 10.1007/s00012–017–0462-z.
G. Hutchinson and G. Czédli, A test for identities satisfied in lattices of submodules, Algebra Universalis, 8 (1978), 269–309.
B. Jönsson, Congruence varieties, Algebra Universalis, 10 (1980), 355–394.
C. Mure§an, Cancelling congruences of lattices while kee** their filters and ideals, ar**%20their%20filters%20and%20ideals&publication_year=2017&author=Mure%C2%A7an%2CC"> Google Scholar
J. B. Nation, Varieties whose congruences satisfy certain lattice identities, Algebra Universalis, 4 (1974), 78–88.
A. Urquhart, A topological representation theory for lattices, Algebra Universalis, 8 (1978), 45–58.
F. Wehrung, A solution to Dilworth’s congruence lattice problem, Adv. Math., 216 (2007), 610–625.
F. Wehrung, Schmidt and Pudlâk’s approaches to CLP, Lattice theory: special topics and applications, Vol. 1, Birkhäuser/Springer, Cham, 2014, 235–296.
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Dedicated to the memory of George Allen Hutchinson
Communicated by Á. Szendrei
This research was supported by NFSR of Hungary (OTKA), grant number K 115518, and by the research grant Proprietà d’Ordine Nella Semantica Algebrica delle Logiche Non Classiche of Università degli Studi di Cagliari, Regione Autonoma della Sardegna, L. R. 7/2007, n. 7, 2015, CUP: F72F16002920002.
Acknowledgment.
The referee’s careful work and his hints to simplify the proof of Lemma 3.2 and the second proof of part (i) of Theorem 1.1 are appreciated.
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Czédli, G., Mureşan, C. On principal congruences and the number of congruences of a lattice with more ideals than filters. ActaSci.Math. 85, 363–380 (2019). https://doi.org/10.14232/actasm-018-538-y
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DOI: https://doi.org/10.14232/actasm-018-538-y