Factor-group-generated polar spaces and (multi-)qudits.
Let K be a field of characteristic p > 0, K* the multiplicative group of K and a finite group, where is a p-group and B is a p’-group. Denote by a twisted group algebra of G over K with a 2-cocycle λ ∈ Z²(G,K*). We give necessary and sufficient conditions for G to be of OTP projective K-representation type, in the sense that there exists a cocycle λ ∈ Z²(G,K*) such that every indecomposable -module is isomorphic to the outer tensor product V W of an indecomposable -module V and a simple...
Let S be a commutative complete discrete valuation domain of positive characteristic p, S* the unit group of S, Ω a subgroup of S* and a finite group, where is a p-group and B is a p’-group. Denote by the twisted group algebra of G over S with a 2-cocycle λ ∈ Z²(G,S*). For Ω satisfying a specific condition, we give necessary and sufficient conditions for G to be of OTP projective (S,Ω)-representation type, in the sense that there exists a cocycle λ ∈ Z²(G,Ω) such that every indecomposable...
In the literature, there are several graphs related to a finite group . Two of them are the character degree graph, denoted by , and the prime graph, . In this paper we classify all finite groups whose character degree graphs are disconnected and coincide with their prime graphs. As a corollary, we find all finite groups whose character degree graphs are square and coincide with their prime graphs.
In this paper, we consider finite groups with precisely one nonlinear nonfaithful irreducible character. We show that the groups of order 16 with nilpotency class 3 are the only -groups with this property. Moreover we completely characterize the nilpotent groups with this property. Also we show that if is a group with a nontrivial center which possesses precisely one nonlinear nonfaithful irreducible character then is solvable.
This Note contains the complete list of finite groups, having exactly eight non-linear irreducible characters. In section 4 we consider in full details some typical cases.
Let be a finite group. If has two rows which differ in only one entry in the character table, we call an RD1-group. We investigate the character tables of RD1-groups and get some necessary and sufficient conditions about RD1-groups.
Let be a finite group with exactly two nonlinear non-faithful irreducible characters. We discuss the properties of and classify finite -groups with exactly two nonlinear non-faithful irreducible characters.
Let G be a finite group, K a field of characteristic p > 0, and the twisted group algebra of G over K with a 2-cocycle λ ∈ Z²(G,K*). We give necessary and sufficient conditions for to be of semi-wild representation type in the sense of Drozd. We also introduce the concept of projective K-representation type for a finite group (tame, semi-wild, purely semi-wild) and we exhibit finite groups of each type.
Nous démontrons que dans la catégorie des foncteurs entre espaces vectoriels sur , le produit tensoriel entre le second foncteur injectif standard non constant et un foncteur puissance extérieure est artinien. Seul était antérieurement connu le caractère artinien de cet injectif ; notre résultat constitue une étape pour l’étude du troisième foncteur injectif standard non constant de .Nous utilisons le foncteur de division par le foncteur identité et des considérations issues de la théorie...