CatDat

category of left modules over a non-semisimple ring

This is the special case of RModR{-}\Mod where RR is a ring that is not semisimple. In particular, R0R \neq 0 and RR is not a field. If RR is semisimple, then by the Artin-Wedderburn theorem, the category is equivalent to a finite direct product of categories DModD{-}\Mod for division rings DD, and the case of division rings is in a separate entry.

Satisfied Properties

Assigned properties

Deduced properties

Unsatisfied Properties

Assigned properties

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

Special objects

  • terminal object: zero module
  • initial object: zero module
  • products: direct products with pointwise operations
  • coproducts: direct sums

Special morphisms

  • isomorphisms: bijective morphisms
  • monomorphisms: injective morphisms
  • epimorphisms: surjective morphisms
  • regular monomorphisms: same as monomorphisms
  • regular epimorphisms: surjective morphisms

Indistinguishable categories

These categories in the database currently have exactly the same properties as the category of left modules over a non-semisimple ring. This indicates that the data may be incomplete or that a distinguishing property may be missing from the database.