Every group is a quotient of a free group
Statement
Suppose is a group and is a generating set for . Then, is isomorphic to a Quotient group (?) of a Free group (?) of rank equal to the cardinality of .
More specifically, we let be a set in bijection with , and be the free group on , and we can construct a surjective homomorphism:
which is the unique each element in to its image in under the bijection.
Particular cases
- Every finitely generated group is a quotient of a finitely generated free group.
- In general, every infinite group is a quotient of an infinite free group of the same cardinality.
Related facts
- Free group of rank two is SQ-universal: This states that every finitely generated group is isomorphic to a subquotient of the free group of rank two.
- Cayley's theorem: This states that every group is a subgroup of a symmetric group on itself as a set.
- Every finite group is a subgroup of a finite simple group
- Every group is a subgroup of a simple group
- Every group is a subgroup of a complete group