Nilpotent and abelian Hall subgroups in finite groups
[EN] We give a characterization of the finite groups having nilpotent or abelian Hall pi-subgroups that can easily be verified using the character table.
Existence of normal Hall subgroups by means of orders of products
Let G be a finite group, let π be a set of primes and let p be a prime. We characterize the existence of a normal Hall π‐subgroup in G in terms of the order of products of certain elements of G. This theorem generalizes a characterization of A. Moretó and the second author by using the orders of products of elements for those groups having a normal Sylow p‐subgroup 6. As a consequence, we also give a π‐decomposability criterion for a finite group also by means of the orders of products.
Actions and Invariant Character Degrees
point subgroup. In general, we use the same notation as in 6 and 7 .wx wxPart of the proof of Theorem A depends on the basic properties of theGajendragadkar p-special characters 1 and we assume the reader iswxfamiliar with those. However, we will repeatedly use a deeper fact: anirreducible character a of a Hall p-subgroup
Powers of conjugacy classes in a finite groups
[EN] The aim of this paper is to show how the number of conjugacy classes appearing in the product of classes affect the structure of a finite group. The aim of this paper was to show several results about solvability concerning the case in which the power of a conjugacy class is a union of one or two conjugacy classes. Moreover, we show that the above conditions can be determined through the character table of the group.
Order of products of elements in finite groups
If G is a finite group, p is a prime, and x∈G, it is an interesting problem to place x in a convenient small (normal) subgroup of G, assuming some knowledge of the order of the products xy, for certain p‐elements y of G.
Sylow Normalizers and Brauer Character Degrees
Suppose that G is a finite group. In this note, we show that a local condition about Sylow normalizers is equivalent to a global condition on the degrees of certain irreducible Brauer characters of G. Theorem A. Let G be a finite p; q-solvable group, and let Q ∈ SylqG and P ∈ SylpG. Then every irreducible p-Brauer character of G of q′degree has p′-degree if and only if NGQ is contained in some G-conjugate of NGP. Theorem A needs a solvability hypothesis. If p = 7, then the irreducible p-Brauer characters of the group G = PSL2; 27 have degrees 1; 13; 26; 28. If we set q = 2, then each q′-degree is also a p′-degree.