Automorph-conjugate subgroup

From Groupprops

This article defines a subgroup property: a property that can be evaluated to true/false given a group and a subgroup thereof, invariant under subgroup equivalence. View a complete list of subgroup properties[SHOW MORE]


BEWARE! This term is nonstandard and is being used locally within the wiki. [SHOW MORE]

Definition

Symbol-free definition

A subgroup of a group is termed automorph-conjugate if any subgroup to which it can go via an automorphism of the whole group, is also conjugate to the subgroup.

Definition with symbols

A subgroup H of a group G is termed automorph-conjugate if for any automorphism σ of G, H and σ(H) are conjugate subgroups in G (that is, there exists gG such that σ(H)=gHg1).

In terms of the relation implication operator

The property of being automorph-conjugate can be viewed in terms of the relation implication operator with the relation on the left being that of a subgroup pair being automorphic and the relation on the right being that of a subgroup pair being conjugate in the whole group.

Relation with other properties

Stronger properties

Conjunction with other properties

Metaproperties

Transitivity

The property of being automorph-conjugate does not appear to be transitive.

Trimness

The property of being isomorph-conjugate need not be identity-true. This is because a group may be isomorphic to a proper subgroup of itself, but they are clearly not conjugate in the group.

The property of being isomorph-conjugate is trivially true, that is, the trivial subgroup always satisfies the property in any group.

Intersection-closedness

Is the intersection of automorph-conjugate subgroups always automorph-conjugate?

Intermediate subgroup condition

The property of being automorph-conjugate does not satisfy the intermediate subgroup condition. The result of applying the intermediately operator to the property of being automorph-conjugate gives a property that, in particular, implies the property of being pronormal.