we present the basic results on the representation theory of the alternating groups. our approach is based on clifford theory.

‎there are a few finite groups that are determined up to isomorphism solely by their order, such as $mathbb{z}_{2}$ or $mathbb{z}_{15}$. still other finite groups are determined by their order together with other data, such as the number of elements of each order, the structure of the prime graph, the number of order components, the number of sylow $p$-subgroups for each prime $p$, etc. in this...

‎let $g$ be a finite group and $z(g)$ be the center of $g$‎. ‎for a subset $a$ of $g$‎, ‎we define $k_g(a)$‎, ‎the number of conjugacy classes of $g$ which intersect $a$ non-trivially‎. ‎in this paper‎, ‎we verify the structure of all finite groups $g$ which satisfy the property $k_g(g-z(g))=5$ and classify them‎.

We prove that a knowledge of the character degrees of a finite group G and of their multiplicities determines whether G has a Sylow p-subgroup as a direct factor. An analogous result based on a knowledge of the conjugacy class sizes was known. We prove variations of both results and discuss their similarities.

A class function φ on a finite group G is said to be an order separator if, for every x and y in G\{1} , φ(x) = φ(y) is equivalent to x and y being of the same order. Similarly, φ is said to be a class-size separator if, for every x and y in G \ {1} , φ(x) = φ(y) is equivalent to |CG(x)| = |CG(y)| . In this paper, finite groups whose nonlinear irreducible complex characters are all order separa...

Let G be a finite group, and let Δ(G) the prime graph built on its set of conjugacy class sizes: this is (simple undirected) whose vertices are numbers dividing some size G, two distinct p, q adjacent if only pq divides G. In paper, we characterize structure those groups block square.

The greatest power of a prime $p$ dividing the natural number $n$ will be denoted by $n_p$. Let $Ind_G(g)=|G:C_G(g)|$. Suppose that $G$ is finite group and prime. We prove if there exists an integer $\alpha>0$ such $Ind_G(a)_p\in \{1,p^{\alpha}\}$ for every $a$ $p$-element $x\in G$ $Ind_G(x)_p>1$, then includes normal $p$-complement.