Free Group - Free Abelian Group

Free Abelian Group

Further information: free abelian group

The free abelian group on a set S is defined via its universal property in the analogous way, with obvious modifications: Consider a pair (F, φ), where F is an abelian group and φ: S → F is a function. F is said to be the free abelian group on S with respect to φ if for any abelian group G and any function ψ: S → G, there exists a unique homomorphism f: F → G such that

f(φ(s)) = ψ(s), for all s in S.

The free abelian group on S can be explicitly identified as the free group F(S) modulo the subgroup generated by its commutators, i.e. its abelianisation. In other words, the free abelian group on S is the set of words that are distinguished only up to the order of letters. The rank of a free group can therefore also be defined as the rank of its abelianisation as a free abelian group.

Read more about this topic:  Free Group

Famous quotes containing the words free and/or group:

    “The real American type can never be a ballet dancer. The legs are too long, the body too supple and the spirit too free for this school of affected grace and toe walking.”
    —Isadora Duncan (1878–1927)

    “No other group in America has so had their identity socialized out of existence as have black women.... When black people are talked about the focus tends to be on black men; and when women are talked about the focus tends to be on white women.”
    —bell hooks (b. c. 1955)