Some primitive group rings

Quasi-Primitive Rings and Density Theory

Primitive central idempotents of finite group rings of symmetric groups

Let p be a prime. We denote by Sn the symmetric group of degree n, by An the alternating group of degree n and by Fp the field with p elements. An important concept of modular representation theory of a finite group G is the notion of a block. The blocks are in one-to-one correspondence with block idempotents, which are the primitive central idempotents of the group ring FqG, where q is a prime...

0-primitive Near-rings, Minimal Ideals and Simple Near-rings

We study the structure of 0-primitive near-rings and are able to answer an open question in the theory of minimal ideals in near-rings to the negative, namely if the heart of a zero symmetric subdirectly irreducible near-ring is subdirectly irreducible again. Also, we will be able to classify when a simple near-ring with an identity and containing a minimal left ideal is a Jacobson radical near...

Some Results on Hypercentral Units in Integral Group Rings

In this note we investigate the hypercentral units in integral group rings ZG, where G is not necessarily torsion. One of the main results obtained is the following (Theorem 3.5): if the set of torsion elements of G is a subgroup T of G and if Z2(U) is not contained in CU (T ), then T is either an Abelian group of exponent 4 or a Q∗ group. This extends our earlier result on torsion group rings.

Kimmerle’s Conjecture for Integral Group Rings of Some Alternating Groups

Using the Luthar–Passi method and results of Hertweck, we study the long-standing conjecture of Zassenhaus for integral group rings of alternating groups An, n ≤ 8. As a consequence of our results, we confirm the Kimmerle’s conjecture about prime graphs for those groups.