We give a survey of results on the structure of right and left Engel elements
of a group. We also present some new results in this topic.
In this paper we study the longstanding conjecture of whether there exists a
noninner automorphism of order $p$ for a finite non-abelian $p$-group. We prove
that if $G$ is a finite non-abelian $p$-group such that $G/Z(G)$ is powerful
then $G$ has a noninner automorphism of order $p$ leaving either $\Phi(G)$ or
$\Omega_1(Z(G))$ elementwise fixed.
We associate a graph $\mathcal{N}_{G}$ with a group
We study the set of all determinants of adjacency matrices of graphs with a
given number of vertices.