commutator

noun — 3 senses

commutator

noun

Etymology Back-formation from commutation (in the late 19th century), as is commutate (verb) too.

1

An electrical switch, in a generator or motor, that periodically reverses the direction of an electric current.

2

Group theory, Mathematics, Sciences A binary map in a given group G, given by [g, h] = ghg⁻¹h⁻¹, where g and h are elements of G, which yields the group's identity if and only if the group operation commutes for g and h.

3

A binary map in a given ring R, given by [a, b] = ab − ba, where a and b are elements of R, which yields the ring's zero element if and only if the multiplication operation commutes for a and b.

Derived terms
anticommutator, commutator length, commutatorless, commutator subgroup, multicommutator, self-commutator, subcommutator
Related terms
nilpotent group, solvable group

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.