Rank of an abelian group
The rank of an abelian group is a concept from the mathematical field of algebra. It is a measure for the size of an abelian group.
Definition
For an abelian group agree the following numbers agree:
- The cardinality of a maximum - linearly independent subset
- The dimension of the vector space (see tensor product ).
This number is called the rank of.
Examples and properties
- The rank of a natural number is the same; general the rank of the free abelian group on a set is equal to the cardinality of.
- The group has rank n
- An abelian group is a torsion group if and only if its rank is 0.
- The rank is additive on short exact sequences: Is
- Group Theory