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Quasiunitriangular groups

Published online by Cambridge University Press:  12 March 2014

O. V. Belegradek*
Affiliation:
Kemerovo University, Kemerovo 650043, Russia, E-mail: beleg@kemucnit.kemerovo.su

Extract

For a ring with unit R, which need not be associative, denote the group of upper unitriangular 3 × 3 matrices over R by UT3(R). Let e1 = (1,0,0), e2 = (0,1,0), where (α, β, γ) denotes the matrix

Denote the expanded group (UT3(R), e1, e2) by (R). A. 1. Mal′cev [M] gave an algebraic characterization of the expanded groups of the form (R) as follows. Let h1, h2 be elements of a group H; then (H, h1, h2) is isomorphic to (R), for some R, if and only if

(i) H is 2-step nilpotent;

(ii) CH(hi) are abelian, i = 1,2;

(iii) CH(h1) ∩ CH(h2) = Z(H);

(iv) [CH(h1),h2] = [h1, CH(h2)] = Z(H);

(v) Z(H) is a direct summand in both CH(hi).

(In [M] condition (v) is a bit stronger; the version above is presented in [B2].)

A pair (h1, h2) of elements of a group H is said to be a base if (H, h1, h2) satisfies the conditions (i)–(iv). A. I. Mal′cev [M] found a uniform way of first order interpreting a ring Ring(H, h1, h2) in any group with a base (H, h1, h2); in particular, Ring((R)) ≃ R.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1993

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References

REFERENCES

[B1]Belegradek, O. V., On the Mal'cev correspondence between rings and groups, Proceedings of the 7th Easter Conference on Model Theory, Wendisch-Rietz(DDR), 1989, Humboldt-Universität zu Berlin, Sektion Mathematik, Seminar berichte Nr. 104, pp. 4357.Google Scholar
[B2]Belegradek, O. V., The Mal'cev correspondence revisited, Proceedings of the International Conference on Algebra Dedicated to the Memory of A. I. Mal′cev (Novosibirsk, 1989), (Bokut′, L. A., Ershov, Yu. L. and Koçtrikin, A. I., editors), Contemporary Mathematics, vol. 131, Part 1, American Mathematical Society, Providence, RI, 1992, pp. 3759.Google Scholar
[B3]Belegradek, O. V., Groups elementarily equivalent to UT3(R), Proceedings of the 8th Easter Conference on Model Theory, Wendisch-Rietz (DDR), 1990, Humboldt-Universität zu Berlin, Sektion Mathematik, Seminar berichte Nr. 110, pp. 3138.Google Scholar
[B4]Belegradek, O. V., The Mal′cev correspondence and the undecidability, Siberian Mathematical Journal, vol. 33 (1992), no. 4, pp. 2429, (Russian)Google Scholar
[B5]Belegradek, O. V., On spectrum functions of unitriangular groups, Soviet-French Colloquium on Model Theory, Karaganda (Kazakhstan), June 26–30, 1990, Abstracts of Papers, Karaganda State University, Kagaranda, 1990, pp. 89.Google Scholar
[EF]Eklof, P. and Fischer, E., The elementary theory of Abelian groups. Annals of Mathematical Logic, vol. 4 (1972), pp. 115171.CrossRefGoogle Scholar
[F]Fuchs, L., Infinite Abelian groups. Academic Press, New York, 1970.Google Scholar
[M]Mal′cev, A. I., On a certain correspondence between rings and groups, Matematicheskiǐ Sbornik, vol. 50 (1960), pp. 257266. (Russian)Google Scholar
[V]Videla, C. R., On the model theory of the ring NT(n, R), Journal of Pure and Applied Algebra, vol. 55(1988), pp. 289302.CrossRefGoogle Scholar