Semisimple Artinian ring: Difference between revisions

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===Symbol-free definition===
===Symbol-free definition===


A [[commutative unital ring]] is termed '''semisimple''' if it satisfies the following equivalent conditions:
A [[commutative unital ring]] is termed '''semisimple Artinian''' if it satisfies the following equivalent conditions:


* Every module over it is [[semisimple module|semisimple]]
* Every module over it is [[semisimple module|semisimple]]
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* Every short exact sequence of modules over it, splits
* Every short exact sequence of modules over it, splits
* Its [[global dimension]] is zero
* Its [[global dimension]] is zero
* The ring is semisimple as a module over itself
* The ring is a direct product of finitely many fields


==Relation with other properties==
==Relation with other properties==
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* [[Field]]
* [[Field]]
* [[Finite direct product of fields]]


===Weaker properties===
===Weaker properties===


* [[Zero-dimensional ring]]: {{proofat|[[Semisimple implies zero-dimensional]]}}
* [[Artinian ring]]
* [[Zero-dimensional ring]]
* [[Semiprimitive ring]]: (some people use the term '''semisimple''' for such a ring)

Latest revision as of 16:34, 12 May 2008

This article defines a property of commutative unital rings; a property that can be evaluated for a commutative unital ring
View all properties of commutative unital rings
VIEW RELATED: Commutative unital ring property implications | Commutative unital ring property non-implications |Commutative unital ring metaproperty satisfactions | Commutative unital ring metaproperty dissatisfactions | Commutative unital ring property satisfactions | Commutative unital ring property dissatisfactions

Definition

Symbol-free definition

A commutative unital ring is termed semisimple Artinian if it satisfies the following equivalent conditions:

  • Every module over it is semisimple
  • Every module over it is projective
  • Every module over it is injective
  • Every short exact sequence of modules over it, splits
  • Its global dimension is zero
  • The ring is semisimple as a module over itself
  • The ring is a direct product of finitely many fields

Relation with other properties

Stronger properties

Weaker properties