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Several quantitative characterizations of some specific groups

A. Mohammadzadeh, Ali Reza Moghaddamfar (2017)

Commentationes Mathematicae Universitatis Carolinae

Let G be a finite group and let π ( G ) = { p 1 , p 2 , ... , p k } be the set of prime divisors of | G | for which p 1 < p 2 < < p k . The Gruenberg-Kegel graph of G , denoted GK ( G ) , is defined as follows: its vertex set is π ( G ) and two different vertices p i and p j are adjacent by an edge if and only if G contains an element of order p i p j . The degree of a vertex p i in GK ( G ) is denoted by d G ( p i ) and the k -tuple D ( G ) = ( d G ( p 1 ) , d G ( p 2 ) , ... , d G ( p k ) ) is said to be the degree pattern of G . Moreover, if ω π ( G ) is the vertex set of a connected component of GK ( G ) , then the largest ω -number which divides | G | , is said to be an...

Simple group contain minimal simple groups.

Michael J. J. Barry, Michael B. Ward (1997)

Publicacions Matemàtiques

It is a consequence of the classification of finite simple groups that every non-abelian simple group contains a subgroup which is a minimal simple group.

Small-sum pairs in abelian groups

Reza Akhtar, Paul Larson (2010)

Journal de Théorie des Nombres de Bordeaux

Let G be an abelian group and A , B two subsets of equal size k such that A + B and A + A both have size 2 k - 1 . Answering a question of Bihani and Jin, we prove that if A + B is aperiodic or if there exist elements a A and b B such that a + b has a unique expression as an element of A + B and a + a has a unique expression as an element of A + A , then A is a translate of B . We also give an explicit description of the various counterexamples which arise when neither condition holds.

Solitary quotients of finite groups

Marius Tărnăuceanu (2012)

Open Mathematics

We introduce and study the lattice of normal subgroups of a group G that determine solitary quotients. It is closely connected to the well-known lattice of solitary subgroups of G, see [Kaplan G., Levy D., Solitary subgroups, Comm. Algebra, 2009, 37(6), 1873–1883]. A precise description of this lattice is given for some particular classes of finite groups.

Solvable finite groups with a particular configuration of Fitting sets

Daniela Bubboloni (1995)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

A Fitting set is called elementary if it consists of the subnormal subgroups of the conjugates of a given subgroup. In this paper we analyse the structure of the finite solvable groups in which every Fitting set is the insiemistic union of elementary Fitting sets whose intersection is the subgroup 1.

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