nLab noetherian scheme

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Contents

Contents

1. Definition

Definition 1.1. An algebraic scheme is locally noetherian if it can be covered by a family U αU_\alpha of open subsets of the form U α=SpecR αU_\alpha = Spec R_\alpha where R αR_\alpha are noetherian rings. A scheme is noetherian if it is locally noetherian and quasicompact.

Remark 1.2. If RR is a commutative noetherian ring, then every localization of the form R[f 1]R[f^{-1}] where fRf\in R is also noetherian. If a scheme XX is locally noetherian this implies that there is a base of topology of XX consisting of spectra of noetherian rings. In particular every affine subscheme in XX has a basis of topology of spectra of noetherian rings.

2. Properties

Proposition 2.1. An affine scheme is a spectrum of a noetherian ring precisely if it is a locally noetherian scheme.

Corollary 2.2. Every affine subscheme of a locally noetherian scheme is the spectrum of a noetherian ring. A scheme is noetherian if and only if it has a finite cover by spectra of noetherian rings.

3. References

Last revised on January 11, 2014 at 11:14:11. See the history of this page for a list of all contributions to it.