In this article, we provide counterexamples to a conjecture of M. Pellegrini and P. Shumyatsky which states that each coset the centralizer an involution in finite non-abelian simple group $G$ contains odd order element, unless $G=\text{PSL}(n,2)$ for $n\geq 4$. More precisely, show does not hold alternating $A_{8n}$ all 2$.

A group G is said to be n-centralizer if its number of element centralizers $$\mid {{\,\mathrm{Cent}\,}}(G)\mid =n$$ , an F-group every non-central centralizer contains no other and a CA-group all are abelian. For any non-abelian G, we prove that \frac{G}{Z(G)}\mid \le (n-2)^2$$ $$n 12$$ 2(n-4)^{{log}_2^{(n-4)}}$$ otherwise, which improves earlier result. We arbitrary F-group, then gcd $$(n-2, ...

Let X/K be an absolutely simple abelian variety over a number field; we study whether the reductions Xp tend to be simple, too. We show that if End(X) is a definite quaternion algebra, then the reduction Xp is geometrically isogenous to the self-product of an absolutely simple abelian variety for p in a set of positive density, while if X is of Mumford type, then Xp is simple for almost all p. ...

We study the notion of Γ-graded commutative algebra for an arbitrary abelian group Γ. The main examples are the Clifford algebras already treated in [2]. We prove that the Clifford algebras are the only simple finitedimensional associative graded commutative algebras over R or C. Our approach also leads to non-associative graded commutative algebras extending the Clifford algebras.

An ω-categorical supersimple group is finite-by-abelian-by-finite, and has finite SU -rank. Every definable subgroup is commensurable with an acl(∅)definable subgroup. Every finitely based regular type in a CM-trivial ω-categorical simple theory is non-orthogonal to a type of SU -rank 1. In particular, a supersimple ω-categorical CM-trivial theory has finite SU -rank.

A group is ^-separating if a Boolean power of the group has a unique Boolean algebra. It is proved that a finite subdirectly irreducible group is S-separating if and only if it is non-Abelian. Suppose B is a Boolean ring and G is a group. Let B[G] denote the group ring of G with coefficient ring B. The Boolean power G [B] is defined to be the set of those elements 2e,.g,. EB[G] such that (1) 2e...

A set of quasi-uniform random variables X1, . . . , Xn may be generated from a finite group G and n of its subgroups, with the corresponding entropic vector depending on the subgroup structure of G. It is known that the set of entropic vectors obtained by considering arbitrary finite groups is much richer than the one provided just by abelian groups. In this paper, we start to investigate in mo...

Tetris is a popular puzzle video game, invented in 1984. We formulate two versions of the game as transformation semigroup and use this formulation to view through lens Krohn-Rhodes theory. In variation upon which it restarts if player loses, we find permutation group structures, including symmetric \(S_5\) contains non-abelian simple subgroup. This implies, at least case, that iterated finitar...

We prove that the near hexagon Q(5,2)× L3 has a non-abelian representation in the extra-special 2-group 21+12 + and that the near hexagon Q(5,2)⊗Q(5,2) has a non-abelian representation in the extra-special 2-group 21+18 − . The description of the non-abelian representation of Q(5,2)⊗Q(5,2) makes use of a new combinatorial construction of this near hexagon.