Criterion of Subnormality in a Finite Group: Reduction to Elementary Binary Partitions

2021 ◽  
Vol 313 (S1) ◽  
pp. S194-S200
Author(s):  
F. Sun ◽  
X. Yi ◽  
S. F. Kamornikov
Author(s):  
YANJUN LIU ◽  
WOLFGANG WILLEMS

Abstract Similarly to the Frobenius–Schur indicator of irreducible characters, we consider higher Frobenius–Schur indicators $\nu _{p^n}(\chi ) = |G|^{-1} \sum _{g \in G} \chi (g^{p^n})$ for primes p and $n \in \mathbb {N}$ , where G is a finite group and $\chi $ is a generalised character of G. These invariants give answers to interesting questions in representation theory. In particular, we give several characterisations of groups via higher Frobenius–Schur indicators.


2020 ◽  
Vol 18 (1) ◽  
pp. 1742-1747
Author(s):  
Jianjun Liu ◽  
Mengling Jiang ◽  
Guiyun Chen

Abstract A subgroup H of a finite group G is called weakly pronormal in G if there exists a subgroup K of G such that G = H K G=HK and H ∩ K H\cap K is pronormal in G. In this paper, we investigate the structure of the finite groups in which some subgroups are weakly pronormal. Our results improve and generalize many known results.


2021 ◽  
Vol 58 (2) ◽  
pp. 335-346
Author(s):  
Mackenzie Simper

AbstractConsider an urn containing balls labeled with integer values. Define a discrete-time random process by drawing two balls, one at a time and with replacement, and noting the labels. Add a new ball labeled with the sum of the two drawn labels. This model was introduced by Siegmund and Yakir (2005) Ann. Prob.33, 2036 for labels taking values in a finite group, in which case the distribution defined by the urn converges to the uniform distribution on the group. For the urn of integers, the main result of this paper is an exponential limit law. The mean of the exponential is a random variable with distribution depending on the starting configuration. This is a novel urn model which combines multi-drawing and an infinite type of balls. The proof of convergence uses the contraction method for recursive distributional equations.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jiakuan Lu ◽  
Kaisun Wu ◽  
Wei Meng

AbstractLet 𝐺 be a finite group. An irreducible character of 𝐺 is called a 𝒫-character if it is an irreducible constituent of (1_{H})^{G} for some maximal subgroup 𝐻 of 𝐺. In this paper, we obtain some conditions for a solvable group 𝐺 to be 𝑝-nilpotent or 𝑝-closed in terms of 𝒫-characters.


Author(s):  
SH. RAHIMI ◽  
Z. AKHLAGHI

Abstract Given a finite group G with a normal subgroup N, the simple graph $\Gamma _{\textit {G}}( \textit {N} )$ is a graph whose vertices are of the form $|x^G|$ , where $x\in {N\setminus {Z(G)}}$ and $x^G$ is the G-conjugacy class of N containing the element x. Two vertices $|x^G|$ and $|y^G|$ are adjacent if they are not coprime. We prove that, if $\Gamma _G(N)$ is a connected incomplete regular graph, then $N= P \times {A}$ where P is a p-group, for some prime p, $A\leq {Z(G)}$ and $\textbf {Z}(N)\not = N\cap \textbf {Z}(G)$ .


2016 ◽  
Vol 15 (07) ◽  
pp. 1650138
Author(s):  
Alexandre Turull ◽  
Thomas R. Wolf

Let a finite group [Formula: see text] act coprimely on a finite group [Formula: see text]. The Glauberman–Isaacs correspondence [Formula: see text] is a bijection from the set of [Formula: see text]-invariant irreducible characters of [Formula: see text] onto the set [Formula: see text] of irreducible characters of the centralizer of [Formula: see text] in [Formula: see text]. Let [Formula: see text] be a subgroup of [Formula: see text]. Composing from left to right, it follows that [Formula: see text] is an injection from [Formula: see text] into [Formula: see text]. We show that, in some cases, the map can be defined via the actions of some subgroups of [Formula: see text] containing [Formula: see text] on the centralizers in [Formula: see text] of some other such subgroups. We also show in many instances, such as [Formula: see text] odd or [Formula: see text] supersolvable and [Formula: see text] solvable, that this map is independent of the overgroup [Formula: see text].


1988 ◽  
Vol 103 (3) ◽  
pp. 427-449 ◽  
Author(s):  
John C. Harris ◽  
Nicholas J. Kuhn

LetBGbe the classifying space of a finite groupG. Consider the problem of finding astabledecompositionintoindecomposablewedge summands. Such a decomposition naturally splitsE*(BG), whereE* is any cohomology theory.


Sign in / Sign up

Export Citation Format

Share Document