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Torsion units in integral group rings of some metabelian groups. II. (English) Zbl 0611.16007

This continuation of the work on the Zassenhaus conjecture [see Part I by the two last named authors, J. Algebra 103, 490-499 (1986; Zbl 0603.16010)] uses an entirely new approach which seems to be very interesting and, in the opinion of the authors, might lead to a proof of the Zassenhaus conjecture for groups G of the form \(A\rtimes X\) with A and X abelian and of relatively prime order. Instead of using explicit computations of the representations of G, the well known embedding \(ZG\to (ZA)_ m\) (m\(\times m\) matrices over ZA) is studied. For better application of this context, it is shown that the Zassenhaus conjecture is equivalent to the following statement: ”For every \(u=\sum u_ gg\), a torsion, normalized unit of ZG, there exists an element \(g_ 0\) of G, unique up to conjugation, such that the sum of the coefficients \(u_ g\) of the element g conjugate to \(g_ 0\) is different from zero”. With this new technique, the Zassenhaus conjecture is proved when the order of X, m, is less than the primes dividing the order of A in the following special cases: 1) m is prime; 2) A is cyclic.
Reviewer: H.A.Merklen

MSC:

16U60 Units, groups of units (associative rings and algebras)
16S34 Group rings
20C05 Group rings of finite groups and their modules (group-theoretic aspects)

Citations:

Zbl 0603.16010
Full Text: DOI

References:

[1] Cliff, G., Zero divisors and idempotents in group rings, Canad. J. Math., 32, 596-602 (1980) · Zbl 0439.16011
[2] Cliff, G.; Sehgal, S. K.; Weiss, A., Units of integral group rings of metabelian groups, J. Algebra, 73, 167-185 (1981) · Zbl 0484.16004
[3] Gorenstein, D., (Finite Groups (1968), Harper & Row: Harper & Row New York) · Zbl 0202.02402
[4] Lang, S., (Algebraic Number Theory (1970), Addison-Wesley: Addison-Wesley Reading, Mass) · Zbl 0211.38404
[5] Polcino Milies, C.; Ritter, J.; Sehgal, S. K., On a Conjecture of Zassenhaus on torsion units in integral group rings II, (Proc. Amer. Math. Soc., 97 (1986)), 201-206 · Zbl 0594.16001
[6] Polcino Milies, C.; Sehgal, S. K., Torsion units in integral group rings of metacyclic groups, J. Number Theory, 19, 103-114 (1984) · Zbl 0551.16004
[7] Ritter, J.; Sehgal, S. K., On a Conjecture of Zassenhaus on torsion units in integral group rings, Math. Ann., 264, 257-270 (1983) · Zbl 0521.16006
[8] Sehgal, S. K., (Topic in Group Rings (1978), Dekker: Dekker New York) · Zbl 0411.16004
[9] Sehgal, S. K.; Weiss, A., Torsion units in integral group rings of some metabelian groups, J. Algebra, 103, 490-499 (1986) · Zbl 0603.16010
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