On the Order of Doubly Transitive Permutation Groups.
In this paper as the main result, we determine finite groups with the same prime graph as the automorphism group of a sporadic simple group, except .
Let be a finite group. The prime graph of is a simple graph whose vertex set is and two distinct vertices and are joined by an edge if and only if has an element of order . A group is called -recognizable by prime graph if there exist exactly nonisomorphic groups satisfying the condition . A 1-recognizable group is usually called a recognizable group. In this problem, it was proved that is recognizable, if is an odd prime and is odd. But for even , only the recognizability...
We investigate the situation when the inner mapping group of a commutative loop is of order , where is a prime number, and we show that then the loop is solvable.
Loop capable groups are groups which are isomorphic to inner mapping groups of loops. In this paper we show that abelian groups , where and is an odd prime, are not loop capable groups. We also discuss generalizations of this result.
In this paper we consider finite loops and discuss the problem which nilpotent groups are isomorphic to the inner mapping group of a loop. We recall some earlier results and by using connected transversals we transform the problem into a group theoretical one. We will get some new answers as we show that a nilpotent group having either , as the Sylow -subgroup for some odd prime or the group of quaternions as the Sylow -subgroup may not be loop capable.