scholarly journals On infinite groups in which all abelian subgroups are locally cyclic

Author(s):  
Costantino Delizia ◽  
Chiara Nicotera

AbstractThe structure of locally soluble periodic groups in which every abelian subgroup is locally cyclic was described over 20 years ago. We complete the aforementioned characterization by dealing with the non-periodic case. We also describe the structure of locally finite groups in which all abelian subgroups are locally cyclic.

2014 ◽  
Vol 12 (12) ◽  
Author(s):  
Leonid Kurdachenko ◽  
Sevgi Atlıhan ◽  
Nikolaj Semko

AbstractThe main aim of this article is to examine infinite groups whose non-abelian subgroups are subnormal. In this sense we obtain here description of such locally finite groups and, as a consequence we show several results related to such groups.


1998 ◽  
Vol 08 (04) ◽  
pp. 443-466 ◽  
Author(s):  
Lev S. Kazarin ◽  
Leonid A. Kurdachenko ◽  
Igor Ya. Subbotin

Groups with the weak maximal condition on non-abelian subgroups are the main subject of this research. Locally finite groups with this property are abelian or Chemikov. Non-abelian groups with the weak maximal condition on non-abelian subgroups, which have an ascending series of normal subgroups with locally nilpotent or locally finite factors, are described in this article.


It is known that two groups with an amalgamated subgroup can be embedded in a group, and if the given groups are finite, the embedding group can be chosen finite. The present paper deals with the question how ‘finite’ can here be relaxed to ‘locally finite’, ‘of finite exponent’, or ‘periodic’. An example shows that two locally finite groups of finite exponent, with an amalgamated subgroup, may not be embeddable even in a periodic group. Conditions that ensure the possibility of such embeddings are then investigated. The principal tool is the ‘permutational product’ of groups that has recently been introduced into the investigation of other embedding problems.


2018 ◽  
Vol 17 (01) ◽  
pp. 1850005
Author(s):  
Fernando Szechtman ◽  
Anatolii Tushev

Necessary and sufficient conditions for a group to possess a faithful irreducible representation are investigated. We consider locally finite groups and groups whose socle is essential.


2014 ◽  
Vol 17 (5) ◽  
Author(s):  
Mehdi Rajabian ◽  
Mohammad Farrokhi D. G. ◽  
Ahmad Erfanian

AbstractWe will determine all infinite 2-locally finite groups and all infinite 2-groups with planar subgroup graph, and show that infinite groups that satisfy the chain conditions and contain an involution do not have planar embeddings. We also determine all connected outer-planar groups and outer-planar groups satisfying the chain conditions. As a result, we obtain all planar groups that are direct products of connected groups.


2019 ◽  
Vol 62 (1) ◽  
pp. 183-186
Author(s):  
KIVANÇ ERSOY

AbstractIn Ersoy et al. [J. Algebra481 (2017), 1–11], we have proved that if G is a locally finite group with an elementary abelian p-subgroup A of order strictly greater than p2 such that CG(A) is Chernikov and for every non-identity α ∈ A the centralizer CG(α) does not involve an infinite simple group, then G is almost locally soluble. This result is a consequence of another result proved in Ersoy et al. [J. Algebra481 (2017), 1–11], namely: if G is a simple locally finite group with an elementary abelian group A of automorphisms acting on it such that the order of A is greater than p2, the centralizer CG(A) is Chernikov and for every non-identity α ∈ A the set of fixed points CG(α) does not involve an infinite simple groups then G is finite. In this paper, we improve this result about simple locally finite groups: Indeed, suppose that G is a simple locally finite group, consider a finite non-abelian subgroup P of automorphisms of exponent p such that the centralizer CG(P) is Chernikov and for every non-identity α ∈ P the set of fixed points CG(α) does not involve an infinite simple group. We prove that if Aut(G) has such a subgroup, then G ≅PSLp(k) where char k ≠ p and P has a subgroup Q of order p2 such that CG(P) = Q.


Author(s):  
Olivia Caramello

This chapter discusses several classical as well as new examples of theories of presheaf type from the perspective of the theory developed in the previous chapters. The known examples of theories of presheaf type that are revisited in the course of the chapter include the theory of intervals (classified by the topos of simplicial sets), the theory of linear orders, the theory of Diers fields, the theory of abstract circles (classified by the topos of cyclic sets) and the geometric theory of finite sets. The new examples include the theory of algebraic (or separable) extensions of a given field, the theory of locally finite groups, the theory of vector spaces with linear independence predicates and the theory of lattice-ordered abelian groups with strong unit.


1976 ◽  
Vol 43 (1) ◽  
pp. 168-175 ◽  
Author(s):  
Angus Macintyre ◽  
Saharon Shelah

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