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Pushforwardable automorphism

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This article defines an automorphism property, viz a property of group automorphisms. Hence, it also defines a function property (property of functions from a group to itself)
View other automorphism properties OR View other function properties
This term is related to: Extensible Automorphisms Problem
See more terms related to Extensible Automorphisms Problem OR see facts/theorems related to Extensible Automorphisms Problem


Contents

BEWARE! This term is nonstandard and is being used locally within the wiki. For its use outside the wiki, please define the term when using it. If you are aware of an equivalent standard term, please leave a comment on the talk page
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This is a variation of inner automorphism
View a complete list of variations of inner automorphism OR read a survey article on varying inner automorphism

Definition

Symbol-free definition

An automorphism of a group is termed pushforwardable if it can be pushed forward via any homomorphism from that group to any group.

Definition with symbols

An automorphism σ of a group G is termed extensible if, for any homomorphism π from G to any group H, there is an automorphism φ of H such that π.σ = φ.π.

In terms of the pushforwardability operator

The automorphism property of being pushforwardable is the result of applying the pushforwardability operator to the tautology.

Relation with other properties

This property is conjectured to equal the property: inner automorphism

Stronger properties

Weaker properties

Metaproperties

Group-closedness

This automorphism property is group-closed: it is closed under the group operations on automorphisms (composition, inversion and the identity map). It follows that the subgroup comprising automorphisms with this property, is a normal subgroup of the automorphism group
View a complete list of group-closed automorphism properties

The pushforwardable automorphisms of a group form a subgroup of its automorphism group. This follows from the fact that the pushforward of the product of two automorphisms can be taken as the product of their pushforwards, and the pushforward of the inverse of an automorphism can be taken as the inverse of the pushforward.

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