Localization respects associated primes for Noetherian rings: Difference between revisions

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(New page: ==Statement== Suppose <math>A</math> is a Noetherian commutative unital ring and <math>M</math> is any <math>A</math>-module (not necessarily finitely generate...)
 
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{{Noetherian ring result}}
==Statement==
==Statement==


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<math>Ass_{S^{-1}A}S^{-1}M = Ass_AM \cap Spec(S^{-1}A)</math>
<math>Ass_{S^{-1}A}S^{-1}M = Ass_AM \cap Spec(S^{-1}A)</math>
==Proof==
The key ingredient in the proof is the fact that if <math>m \in M</math>, the union of annihilators of all elements of <math>Sm</math>, can be realized as the annihilator of a ''single'' element <math>sm</math>.

Latest revision as of 16:26, 12 May 2008

This article defines a result where the base ring (or one or more of the rings involved) is Noetherian
View more results involving Noetherianness or Read a survey article on applying Noetherianness

Statement

Suppose A is a Noetherian commutative unital ring and M is any A-module (not necessarily finitely generated. Let S be a multiplicatively closed subset of A.

There is a natural inclusion on spectra:

Spec(S1A)Spec(A)

The set of associated primes for S1M as an S1A-module is the inverse image in Spec(S1A) of the set of associated primes for M as an A-module.

If we identify Spec(S1A) with its image, a subset of Spec(A), then we can write:

AssS1AS1M=AssAMSpec(S1A)

Proof

The key ingredient in the proof is the fact that if mM, the union of annihilators of all elements of Sm, can be realized as the annihilator of a single element sm.