Affine scheme: Difference between revisions

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imported>Aleksander Stos
m (Affine Scheme moved to Affine scheme: convention)
imported>Giovanni Antonio DiMatteo
Line 3: Line 3:
For a commutative ring <math>A</math>, the set <math>Spec(A)</math> (called the ''prime spectrum of ''<math>A</math>) denotes the set of prime ideals of $A$. This set is endowed with a [[Topological Space|topology]] of closed sets, where closed subsets are defined to be of the form  
For a commutative ring <math>A</math>, the set <math>Spec(A)</math> (called the ''prime spectrum of ''<math>A</math>) denotes the set of prime ideals of $A$. This set is endowed with a [[Topological Space|topology]] of closed sets, where closed subsets are defined to be of the form  
:<math>V(E)=\{p\in Spec(A)| p\supseteq E\}</math>  
:<math>V(E)=\{p\in Spec(A)| p\supseteq E\}</math>  
for any subset <math>E\subseteq A</math>.  This topology of closed sets is called the ''Zariski topology'' on <math>Spec(A)</math>.
for any subset <math>E\subseteq A</math>.  This topology of closed sets is called the ''Zariski topology'' on <math>Spec(A)</math>. It is easy to check that <math>V(E)=V\left((E)\right)=V(\sqrt{(E)})</math>, where
<math>(E)</math> is the ideal of <math>A</math> generated by <math>E</math>.


==Some Topological Properties==
==Some Topological Properties==

Revision as of 12:42, 9 December 2007

Definition

For a commutative ring , the set (called the prime spectrum of ) denotes the set of prime ideals of $A$. This set is endowed with a topology of closed sets, where closed subsets are defined to be of the form

for any subset . This topology of closed sets is called the Zariski topology on . It is easy to check that , where is the ideal of generated by .

Some Topological Properties

is Hausdorff

The Structural Sheaf

The Category of Affine Schemes

Regarding as a contravariant functor between the category of commutative rings and the category of affine schemes, one can show that it is in fact an anti-equivalence of categories.


Curves