A Chevalley scheme in
algebraic geometry
Algebraic geometry is a branch of mathematics, classically studying zeros of multivariate polynomials. Modern algebraic geometry is based on the use of abstract algebraic techniques, mainly from commutative algebra, for solving geometrical ...
was a precursor notion of
scheme theory
In mathematics, a scheme is a mathematical structure that enlarges the notion of algebraic variety in several ways, such as taking account of multiplicities (the equations ''x'' = 0 and ''x''2 = 0 define the same algebraic variety but different sc ...
.
Let ''X'' be a separated integral
noetherian scheme In algebraic geometry, a noetherian scheme is a scheme that admits a finite covering by open affine subsets \operatorname A_i, A_i noetherian rings. More generally, a scheme is locally noetherian if it is covered by spectra of noetherian rings. Thus ...
, ''R'' its
function field. If we denote by
the set of subrings
of ''R'', where ''x'' runs through ''X'' (when
, we denote
by
),
verifies the following three properties
* For each
, ''R'' is the field of fractions of ''M''.
* There is a finite set of noetherian subrings
of ''R'' so that
and that, for each pair of indices ''i,j'', the subring
of ''R'' generated by
is an
-algebra of finite type.
* If
in
are such that the maximal ideal of ''M'' is contained in that of ''N'', then ''M=N''.
Originally,
Chevalley also supposed that R was an extension of finite type of a field K and that the
's were algebras of finite type over a field too (this simplifies the second condition above).
Bibliography
Online{{Webarchive, url=https://web.archive.org/web/20160306015028/http://numdam.org/numdam-bin/feuilleter?id=pmihes_1960__4_ , date=2016-03-06
Scheme theory