×

On the probability of zero divisor elements in group rings. (English) Zbl 1518.16026

Let \(R\) be a non-trivial finite commutative ring with identity and \(G\) be a finite group. Let \(P(RG)\) denote the probability that the product of two randomly chosen elements of the group ring \(RG\) is zero. The author proves that \(P(RG) \geq 1/4\) if and only if \(RG\) is isomorphic to one of the following rings: \( \mathbb{Z}_2 C_2\), \(\mathbb{Z}_3 C_2\), \(\mathbb{Z}_2 C_3\) (Theorem 3.10). Furthermore, there are established some upper and lower bounds for \(P(RG)\) (Lemmas 3.8, 3.9). In particular, the author obtains some formulas for calculations of \(P(RG)\) in the case, where \(R\) is a finite field and \(|G| \leq 4\) (Theorems 3.1, 3.2, 3.3, 3.4).

MSC:

16S34 Group rings
16U60 Units, groups of units (associative rings and algebras)
Full Text: DOI

References:

[1] [1] J. Gildea, The structure of the unit group of the group algebra F3K (C3 × D6 ), Comm. Algebra, 38 (2010) 3311-3317. · Zbl 1202.16030
[2] [2] M. A. Esmkhani and S. M. Jafarian Amiri, The probability that the multiplication of two ring elements is zero, J. Algebra Appl., 17 (2018) pp. 9. · Zbl 1387.13055
[3] [3] N. Makhijani, R. K. Sharma and J. B. Srivastava, The unit group of algebra of circulant matrices, Int. J. Group Theory, 3 no. 4 (2014) 13-16. · Zbl 1335.16028
[4] [4] J. Gildea and L. Creedon, The structure of the unit group of the group algebra F 3k D6 , Int. J. Pure Appl. Math, 45, no. 2, (2008) 315-320. · Zbl 1145.16308
[5] [5] J. Gildea, The structure of the unitary units of the group algebra F2k D8 , Int. Electron. J. Algebra, 9 (2011) 171-176. · Zbl 1253.16035
[6] [6] J. Gildea, On the order of U (Fpk D2pm ), Int. J. Pure Appl. Math., 46 (2008) 267-272. · Zbl 1149.16303
[7] [7] G. Tang and Y. Gao, The unit groups of F G of groups with order 12, Int. J. Pure Appl. Math., 73 (2011) 143-158. · Zbl 1244.16031
[8] [8] M. Khan, R. K. Sharma and J. B. Srivastava, The unit group of F S4 , Acta Math. Hungar., 118 (2008) 105-113. · Zbl 1156.16024
[9] [9] C. P. Milies and S. K. Sehgal, An introduction to group rings,Springer Science and Business Media, 1, Kluwer Academic publishers Dordrecht/Boston/London, 2002. · Zbl 0997.20003
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.