Complex analytic space

Complex analytic space

In mathematics, a complex analytic space is a generalization of a complex manifold which allows the presence of singularities. Complex analytic spaces are locally ringed spaces which 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.

Definition

Denote the constant sheaf on a topological space with value C by \underline\mathbf{C}. A C-space is a locally ringed space (X, \mathcal{O}_X) whose structure sheaf is an algebra over \underline\mathbf{C}.

Choose an open subset U of some complex affine space Cn, and fix finitely many holomorphic functions f1, ..., fk in U. Let X = V(f1, ..., fk) be the common vanishing locus of these holomorphic functions, that is, X = {x|f1(x) = ... = fk(x) = 0}. Define a sheaf of rings on X by letting \mathcal{O}_X be the restriction to X of \mathcal{O}_U/(f_1, \ldots, f_k), where \mathcal{O}_U is the sheaf of holomorphic functions on U. Then the locally ringed C-space (X, \mathcal{O}_X) is a local model space.

A complex analytic space is a locally ringed C-space (X, \mathcal{O}_X) which is locally isomorphic to a local model space.

References

  • Grauert and Remmert, Complex Analytic Spaces
  • Grauert, Peternell, and Remmert, Encyclopaedia of Mathematical Sciences 74: Several Complex Variables VII

See also