Not signed in (Sign In)

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex complex-geometry computable-mathematics computer-science constructive cosmology definitions deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundation foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory k-theory lie-theory limits linear linear-algebra locale localization logic mathematics measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nforum nlab noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
  1. starting article on semisimple rings

    Anonymous

    v1, current

    • CommentRowNumber2.
    • CommentAuthorJohn Baez
    • CommentTimeJun 17th 2023

    Added two equivalent definitions of “semisimple ring”; changed “semiprimitive” to “with vanishing Jacobson radical” since this is a bit more familiar to many people.

    diff, v2, current

    • CommentRowNumber3.
    • CommentAuthorJohn Baez
    • CommentTimeJun 17th 2023

    Added more examples of semisimple rings, and also examples of simple rings that are not semisimple, with an explanation of why this occurs.

    diff, v2, current

    • CommentRowNumber4.
    • CommentAuthorJohn Baez
    • CommentTimeJul 1st 2023

    Two more characterizations of semisimple rings:

    • Every left RR-module is projective

    • Every right RR-module is projective.

    diff, v3, current

    • CommentRowNumber5.
    • CommentAuthorJoseBrox
    • CommentTimeSep 27th 2023
    The current page says "The ring of linear transformations of an infinite-dimensional vector space over field is also simple but not Artinian and thus not semisimple". This is not true: this ring is prime with socle but not simple, since it does not coincide with its socle, which is the subring (without identity) of linear transformations of finite rank. Some modification is needed.
    • CommentRowNumber6.
    • CommentAuthorJohn Baez
    • CommentTimeOct 3rd 2023

    I don’t follow your logic, since I don’t know much about socles. But I’ll just delete that (non)example.

  2. Added algebra - contentx to context sidebar

    Anonymouse

    diff, v5, current