Topic summary
Abelian groups

Extracted from the Wikipedia article Abelian group.
Relation to other mathematical topics
- Amongst torsion-free abelian groups of finite rank, only the finitely generated case and the rank 1 case are well understood.
- There are many unsolved problems in the theory of infinite-rank torsion-free abelian groups.
- While countable torsion abelian groups are well understood through simple presentations and Ulm invariants, the case of countable mixed groups is much less mature.
- Many mild extensions of the first-order theory of abelian groups are known to be undecidable.
- Finite abelian groups remain a topic of research in computational group theory.