we characterize the rational subsets of a finite group and discuss the relations to integral cayley graphs.

let l = u3(9) be the simple projective unitary group in dimension 3 over a eld with 92 elements. in this article, we classify groups with the same order and degree pattern as an almost simple group related to l. since aut(l) = z4 hence almost simple groups related to l are l, l : 2 or l : 4. in fact, we prove that l, l : 2 and l : 4 are od-characterizable.

let $g$ be a finite group‎. ‎we denote by $psi(g)$ the integer $sum_{gin g}o(g)$‎, ‎where $o(g)$ denotes the order of $g in g$‎. ‎here we show that‎ ‎$psi(a_5)< psi(g)$ for every non-simple group $g$ of order $60$‎, ‎where $a_5$ is the alternating group of degree $5$‎. ‎also we prove that $psi(psl(2,7))

The endomorphisms and the automorphisms of a finite abelian p-group are presented in an efficient way. The order of the automorphism group is computed and its structure investigated. Finally the characteristic subgroups are described for p > 2 and the fully invariant subgroups for any p.

Let G be a finite p-group, and let G denote the d-th term of the derived series of G . We show, for p > 5, that G 6= 1 implies logp |G | > 2 d + 3d − 6, and hence we improve a recent result by Mann.

In this paper, we give some new characterizations of finite p-nilpotent groups by using the notion of HC-subgroups and extend several recent results. Mathematics Subject Classification (2010). 20D10, 20D20.

in this paper we define s algebras and show that every finite group can be found in some s algebra.  we define and study the s degree of a finite group and determine the s degree of several classes of finite groups such as cyclic groups, elementary abelian $p$-groups, and dihedral groups $d_p$.

let $h$, $l$ and $x$ be subgroups of a finite group$g$. then $h$ is said to be $x$-permutable with $l$ if for some$xin x$ we have $al^{x}=l^{x}a$. we say that $h$ is emph{$x$-quasipermutable } (emph{$x_{s}$-quasipermutable}, respectively) in $g$ provided $g$ has a subgroup$b$ such that $g=n_{g}(h)b$ and $h$ $x$-permutes with $b$ and with all subgroups (with all sylowsubgroups, respectively) $v$...