CA-group

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This article defines a group property: a property that can be evaluated to true/false for any given group, invariant under isomorphism
View a complete list of group properties
VIEW RELATED: Group property implications | Group property non-implications |Group metaproperty satisfactions | Group metaproperty dissatisfactions | Group property satisfactions | Group property dissatisfactions
DISJUNCTIVE DEFINITION: This article defines a term where the definition (or at least, one of the equivalent definitions) has the form "every A is a B or a C."

History

Origin

The concept and terminology of CA-groups was introduced by Michio Suzuki in his attempts to solve Burnside's conjecture (which later became the odd-order theorem).

Definition

Below are listed some equivalent definitions of CA-group, also called centralizer is abelian group:

No. Shorthand A group is termed a CN-group if ... A group G is termed a CN-group if ...
1 element centralizers are abelian the centralizer of any non-identity element is an abelian subgroup. for every non-identity element x \in G, the centralizer C_G(x) (i.e., the set of all elements of G that commute with x) is an abelian subgroup of G.
2 subgroup centralizers are abelian the centralizer of any nontrivial subgroup is an abelian subgroup. for every nontrivial subgroup H of G, the centralizer C_G(H) is an abelian subgroup of G.
3 subgroups: abelian or centerless every subgroup of the group is either an abelian group or a centerless group. for every nontrivial subgroup H of G, either H is abelian or H is centerless, i.e., the center of H is trivial.

Equivalence of definitions

Further information: equivalence of definitions of CA-group

Metaproperties

Metaproperty name Satisfied? Proof Statement with symbols
subgroup-closed group property Yes direct from version (3) of the definition Suppose G is a CA-group and H is a subgroup of G. Then, H is also a CA-group.
direct product-closed group property Yes Suppose G_i, i \in I are CA-groups. Then, the external direct product \prod_{i \in I} G_i is also a CA-group.

Relation with other properties

Stronger properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
abelian group (by definition) CA not implies abelian |FULL LIST, MORE INFO

Weaker properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
CN-group |FULL LIST, MORE INFO