Search results for "Solvable group"
showing 10 items of 50 documents
A conjecture on the number of conjugacy classes in ap-solvable group
1996
IfG is ap-solvable group, it is conjectured that k(G/O P (G) ≤ |G| p ′. The conjecture is easily obtained for solvable groups as a consequence of R. Knorr’s work on the k(GV) problem. Also, a related result is obtained: k(G/F(G)) is bounded by the index of a nilpotent injector ofG.
p-Parts of Brauer character degrees
2014
Abstract Let G be a finite group and let p be an odd prime. Under certain conditions on the p-parts of the degrees of its irreducible p-Brauer characters, we prove the solvability of G. As a consequence, we answer a question proposed by B. Huppert in 1991: If G has exactly two distinct irreducible p-Brauer character degrees, then is G solvable? We also determine the structure of non-solvable groups with exactly two irreducible 2-Brauer character degrees.
Number of Sylow subgroups in $p$-solvable groups
2003
If G is a finite group and p is a prime number, let vp(G) be the number of Sylow p-subgroups of G. If H is a subgroup of a p-solvable group G, we prove that v p (H) divides v p (G).
A bound on the p-length of p-solvable groups
2013
Let G be a finite p-solvable group and P a Sylow p-subgroup of G. Suppose that $\gamma_{l(p-1)}(P)\subseteq \gamma_r(P)^{p^s}$ for $l(p-1)<r+s(p-1)$, then the p-length is bounded by a function depending on l.
Séparation des orbites coadjointes d'un groupe exponentiel par leur enveloppe convexe
2008
Resume Revenant sur la question de la separation des representations unitaires irreductibles d'un groupe de Lie exponentiel G par leur application moment, nous presentons ici une nouvelle solution : au lieu de prolonger l'application moment a l'algebre enveloppante de G , nous proposons de definir une application (non lineaire) Φ de g ∗ dans le dual g + ∗ de l'algebre de Lie d'un groupe resoluble G + , de prolonger les representations de G a G + de telle facon que les orbites coadjointes correspondantes de G + soient caracterisees par l'adherence de leur enveloppe convexe. Ceci nous permet de separer les representations irreductibles de G .
On the number of conjugacy classes of zeros of characters
2004
Letm be a fixed non-negative integer. In this work we try to answer the following question: What can be said about a (finite) groupG if all of its irreducible (complex) characters vanish on at mostm conjugacy classes? The classical result of Burnside about zeros of characters says thatG is abelian ifm=0, so it is reasonable to expect that the structure ofG will somehow reflect the fact that the irreducible characters vanish on a bounded number of classes. The same question can also be posed under the weaker hypothesis thatsome irreducible character ofG hasm classes of zeros. For nilpotent groups we shall prove that the order is bounded by a function ofm in the first case but only the derive…
p-Brauer characters ofq-defect 0
1994
For ap-solvable groupG the number of irreducible Brauer characters ofG with a given vertexP is equal to the number of irreducible Brauer characters of the normalizer ofP with vertexP. In this paper we prove in addition that for solvable groups one can control the number of those characters whose degrees are divisible by the largest possibleq-power dividing the order of |G|.
Restriction of characters to Sylow normalizers
2001
Suppose that G is a finite p -solvable group and let \chi \in {\rm Irr}(G) be of p^\prime -degree. In this note, we investigate when \chi remains irreducible when restricted to {\bf {N)}_{G}(P) .
A series of finite groups and related symmetric designs
2007
For any odd prime power q = pe we study a certain solvable group G of order q2 · ((q-1)/2)2 · 2 and construct from its internal structure a symmetric design D with parameters (2q2+1, q2, (q2-1)/2) on which G acts as an automorphism group. As a consequence we find that the full automorphism group of D contains a subgroup of order |G| · e2.
The number of lifts of a Brauer character with a normal vertex
2011
AbstractIn this paper we examine the behavior of lifts of Brauer characters in p-solvable groups. In the main result, we show that if φ∈IBr(G) has a normal vertex Q and either p is odd or Q is abelian, then the number of lifts of φ is at most |Q:Q′|. As a corollary, we prove that if φ∈IBr(G) has an abelian vertex subgroup Q, then the number of lifts of φ in Irr(G) is at most |Q|.