scholarly journals Duality for finite abelian hypergroups over splitting fields

1979 ◽  
Vol 20 (1) ◽  
pp. 57-70 ◽  
Author(s):  
J.R. McMullen ◽  
J.F. Price

A duality theory for finite abelian hypergroups over fairly general fields is presented, which extends the classical duality for finite abelian groups. In this precise sense the set of conjugacy classes and the set of characters of a finite group are dual as hypergroups.

1969 ◽  
Vol 21 ◽  
pp. 684-701 ◽  
Author(s):  
Benson Samuel Brown

Our aim in this paper is to prove the general mod ℭ suspension theorem: Suppose that X and Y are CW-complexes,ℭ is a class offinite abelian groups, and that(i) πi(Y) ∈ℭfor all i < n,(ii) H*(X; Z) is finitely generated,(iii) Hi(X;Z) ∈ℭfor all i > k.Then the suspension homomorphismis a(mod ℭ) monomorphism for 2 ≦ r ≦ 2n – k – 2 (when r= 1, ker E is a finite group of order d, where Zd∈ ℭ and is a (mod ℭ) epimorphism for 2 ≦ r ≦ 2n – k – 2The proof is basically the same as the proof of the regular suspension theorem. It depends essentially on (mod ℭ) versions of the Serre exact sequence and of the Whitehead theorem.


2020 ◽  
pp. 1-7
Author(s):  
Omar Tout

Abstract It is well known that the pair $(\mathcal {S}_n,\mathcal {S}_{n-1})$ is a Gelfand pair where $\mathcal {S}_n$ is the symmetric group on n elements. In this paper, we prove that if G is a finite group then $(G\wr \mathcal {S}_n, G\wr \mathcal {S}_{n-1}),$ where $G\wr \mathcal {S}_n$ is the wreath product of G by $\mathcal {S}_n,$ is a Gelfand pair if and only if G is abelian.


2013 ◽  
Vol 88 (3) ◽  
pp. 448-452 ◽  
Author(s):  
RAJAT KANTI NATH

AbstractThe commutativity degree of a finite group is the probability that two randomly chosen group elements commute. The object of this paper is to compute the commutativity degree of a class of finite groups obtained by semidirect product of two finite abelian groups. As a byproduct of our result, we provide an affirmative answer to an open question posed by Lescot.


2015 ◽  
Vol 08 (04) ◽  
pp. 1550070 ◽  
Author(s):  
Vipul Kakkar ◽  
Laxmi Kant Mishra

In this paper, we define a new graph [Formula: see text] on a finite group [Formula: see text], where [Formula: see text] is a divisor of [Formula: see text]. The vertices of [Formula: see text] are the subgroups of [Formula: see text] of order [Formula: see text] and two subgroups [Formula: see text] and [Formula: see text] of [Formula: see text] are said to be adjacent if there exists [Formula: see text] [Formula: see text] such that [Formula: see text], where [Formula: see text] [Formula: see text] denote the set of all NRTs of [Formula: see text] in [Formula: see text]. We shall discuss the completeness of [Formula: see text] for various groups like finite abelian groups, dihedral groups and some finite [Formula: see text]-groups.


2019 ◽  
Vol 19 (10) ◽  
pp. 2050198
Author(s):  
Ashish Goyal ◽  
Hemant Kalra ◽  
Deepak Gumber

Let [Formula: see text] be a finite group and let [Formula: see text] denote the probability that a randomly chosen element from [Formula: see text] fixes a randomly chosen element from [Formula: see text]. We classify all finite abelian groups [Formula: see text] such that [Formula: see text] in the cases when [Formula: see text] is the smallest prime dividing [Formula: see text], and when [Formula: see text] is any prime. We also compute [Formula: see text] for some classes of finite groups. As a consequence of our results, we deduce that if [Formula: see text] is a finite [Formula: see text]-group having a cyclic maximal subgroup, then [Formula: see text] divides [Formula: see text].


2020 ◽  
Vol 18 (1) ◽  
pp. 1025-1029
Author(s):  
Jinxing Zhao ◽  
Guixin Deng

Abstract Let G be a finite group. The subgroup intersection graph \text{&#x0393;}(G) of G is a graph whose vertices are non-identity elements of G and two distinct vertices x and y are adjacent if and only if |\langle x\rangle \cap \langle y\rangle |\gt 1 , where \langle x\rangle is the cyclic subgroup of G generated by x. In this paper, we show that two finite abelian groups are isomorphic if and only if their subgroup intersection graphs are isomorphic.


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 $\textbf {Z}(N)\not = N\cap \textbf {Z}(G)$ .


1993 ◽  
Vol 160 (2) ◽  
pp. 441-460 ◽  
Author(s):  
L.G. Kovacs ◽  
G.R. Robinson

Author(s):  
BJÖRN SCHUSTER

For any fixed prime p and any non-negative integer n there is a 2(pn − 1)-periodic generalized cohomology theory K(n)*, the nth Morava K-theory. Let G be a finite group and BG its classifying space. For some time now it has been conjectured that K(n)*(BG) is concentrated in even dimensions. Standard transfer arguments show that a finite group enjoys this property whenever its p-Sylow subgroup does, so one is reduced to verifying the conjecture for p-groups. It is easy to see that it holds for abelian groups, and it has been proved for some non-abelian groups as well, namely groups of order p3 ([7]) and certain wreath products ([3], [2]). In this note we consider finite (non-abelian) 2-groups with maximal normal cyclic subgroup, i.e. dihedral, semidihedral, quasidihedral and generalized quaternion groups of order a power of two.


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