Equivalence of dimension notions for affine domain: Difference between revisions

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==Statement==
==Statement==


Let <math>A</math> be an [[affine domain]] over a [[field]] <math>k</math>, i.e. a finitely generated algebra over <math>k</math>, that also happens to be an integral domain. Then, the following are equivalent:
Let <math>A</math> be an [[affine domain]] over a [[field]] <math>k</math>, i.e. a finitely generated algebra over <math>k</math>, that also happens to be an integral domain. Then, the following are equal:


* The [[Krull dimension]] of <math>A</math>
* The [[Krull dimension]] of <math>A</math>
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* Proving that the Krull dimension of the polynomial ring in <math>n</math> variables, is equal to exactly <math>n</math>
* Proving that the Krull dimension of the polynomial ring in <math>n</math> variables, is equal to exactly <math>n</math>
* [[Noether normalization theorem]]
* [[Going up theorem]]
* [[Going up theorem]]
* [[Going down for integral extensions of normal domains]]
* [[Going down for integral extensions of normal domains]]

Latest revision as of 16:19, 12 May 2008

This fact is an application of the following pivotal fact/result/idea: Noether normalization theorem
View other applications of Noether normalization theorem OR Read a survey article on applying Noether normalization theorem

This fact is an application of the following pivotal fact/result/idea: going down
View other applications of going down OR Read a survey article on applying going down

Statement

Let A be an affine domain over a field k, i.e. a finitely generated algebra over k, that also happens to be an integral domain. Then, the following are equal:

  • The Krull dimension of A
  • The Krull dimension of the localization of A at any maximal ideal (which is the same as that obtained using the Hilbert-Samuel polynomial)
  • The transcendence degree of the field of fractions of A, over k

Facts used

Proof

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