The simple group of order 2520

The Simple Group of Order 2520

The Simple Group of Order 168 and K3 Surfaces

The aim of this note is to characterize a K3 surface of Klein-Mukai type in terms of its symmetry.

THE AUTOMORPHISM GROUP OF NON-ABELIAN GROUP OF ORDER p^4

Let G be a finite non-abelian group of order p^4 . In this paper we give a structure theorem for the Sylow p-subgroup, Aut_p(G)  , of the automorphism group of G.

A note on the order graph of a group

 The order graph of a group $G$, denoted by $Gamma^*(G)$, is a graph whose vertices are subgroups of $G$ and two distinct vertices $H$ and $K$ are adjacent if and only if $|H|big{|}|K|$ or $|K|big{|}|H|$. In this paper, we study the connectivity and diameter of this  graph. Also we give a relation between the order graph and prime  graph of a group.

AUTOMORPHISM GROUP OF GROUPS OF ORDER pqr

H"{o}lder in 1893 characterized all groups of order $pqr$ where  $p>q>r$ are prime numbers. In this paper,  by using new presentations of these groups, we compute their full automorphism group.