Graded ring: Difference between revisions

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(New page: ==Definition== A '''graded ring''' is a commutative unital ring <math>A</math> equipped with a direct sum decomposition as a sum of Abelian subgroups: <math>A = \oplus_{i=0}^\infty A...)
 
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{{ring with addl structure}}
==Definition==
==Definition==



Revision as of 21:53, 8 February 2008

This article defines a notion of a ring with additional structure

Definition

A graded ring is a commutative unital ring A equipped with a direct sum decomposition as a sum of Abelian subgroups:

A=i=0Ai=A0A1A2

such that the following hold:

  • Each Ai is a subgroup under addition
  • 1A0
  • AmAnAm+n. In other words, if aAm and bAn then abAm+n

A structure of the above sort on a ring is termed a gradation, also a Z-gradation.

There are related notions for noncommutative rings.

Related notions

Weaker notions