Wikipedia / Complex analytic variety
Wikipedia / Complex analytic variety
In mathematics, particularly differential geometry and complex geometry, a complex analytic variety or complex analytic space is a generalization of a complex manifold that allows the presence of singularities. Complex analytic varieties are locally ringed spaces that are locally isomorphic to local model spaces, where a local model space is an open subset of the vanishing locus of a finite set of holomorphic functions.
Complex analytic varieties are analogous to algebraic varieties. Roughly speaking, a complex analytic variety is a zero locus of a set of a complex analytic function, while an algebraic variety is a zero locus of a set of a polynomial function.
Definition
Denote the constant sheaf on a topological space. A -space is a locally ringed space, whose structure sheaf is an algebra.
of some complex affine space is a local model space.
A complex analytic variety that is locally isomorphic to a local model space.
Morphisms of complex analytic varieties are defined to be morphisms of the underlying locally ringed spaces, they are also called holomorphic maps. A structure sheaf may have nilpotent elements; if the structure sheaf is reduced, then the complex analytic space is called reduced.
An associated complex analytic space (variety) is such that:
Let X be a scheme of finite type) (Spectrum of a ring is an algebra of finite type. Here, the scheme X is obtained by glueing is reduced.
See also
Note
Annotation
References
(no.10-13)
Future reading
External links
Kiran Kedlaya. 18.726 Algebraic Geometry (LEC # 30 - 33 GAGA)Spring 2009. Massachusetts Institute of Technology: MIT OpenCourseWare Creative Commons BY-NC-SA.
Tasty Bits of Several Complex Variables (p.137) open source book by Jiří Lebl BY-NC-SA.