Automorphism-invariant norm

From Commalg

This article defines a property that can be evaluated for a norm on a commutative unital ring: a function from the nonzero elements of the ring to the integers.
View a complete list of properties of norms

Definition

A norm on a commutative unital ring is termed an automorphism-invariant norm if for any nonzero element of the ring and any automorphism of the ring, the norm of the element equals the norm of its image under the automorphism.