Displaying 121 – 140 of 340

Showing per page

Intersecting maximals

A. L. Gilotti, U. Tiberio (2002)

Bollettino dell'Unione Matematica Italiana

Given a class X of finite groups and a finite group G , the authors study the subgroup X G intersection of maximal subgroups that do not belong to X .

Los retículos de las clases de Schunck normales y de las clases derivadas.

Julio Lafuente López (1979)

Revista Matemática Hispanoamericana

All groups to be considered are finite. The main result of this paper is the following: the normal Schunck classes compose a complete and distributive lattice antiisomorphic to the lattice composed by the Derived classes (s. [5]). It begins with a first section of machinery which establishes that the Derived classes are precisely the classes of groups G such that every simple section of G appartains to a σ-closed class (s. 1.6) of simple groups; therefore the Derived classes are a natural generalization...

Maximal subgroups and PST-groups

Adolfo Ballester-Bolinches, James Beidleman, Ramón Esteban-Romero, Vicent Pérez-Calabuig (2013)

Open Mathematics

A subgroup H of a group G is said to permute with a subgroup K of G if HK is a subgroup of G. H is said to be permutable (resp. S-permutable) if it permutes with all the subgroups (resp. Sylow subgroups) of G. Finite groups in which permutability (resp. S-permutability) is a transitive relation are called PT-groups (resp. PST-groups). PT-, PST- and T-groups, or groups in which normality is transitive, have been extensively studied and characterised. Kaplan [Kaplan G., On T-groups, supersolvable...

Minimal formations of universal algebras

Wenbin Guo, K.P. Shum (2001)

Discussiones Mathematicae - General Algebra and Applications

A class ℱ of universal algebras is called a formation if the following conditions are satisfied: 1) Any homomorphic image of A ∈ ℱ is in ℱ; 2) If α₁, α₂ are congruences on A and A / α i , i = 1,2, then A/(α₁∩α₂) ∈ ℱ. We prove that any formation generated by a simple algebra with permutable congruences is minimal, and hence any formation containing a simple algebra, with permutable congruences, contains a minimum subformation. This result gives a partial answer to an open problem of Shemetkov and Skiba...

Currently displaying 121 – 140 of 340