normal complex analytic variety
Let be a local complex analytic variety (or a complex analytic space). A point is if and only if every weakly holomorphic function through extends to beholomorphic in near
In particular, if is a complex analytic subvariety, it is normal at if and only if every weakly holomorphic function through extends to be holomorphic in a neighbourhood of in .
To see that this definition is equivalent to the usual one, that is, that is normalat if and only if (the ring of germs of holomorphic functions at )is integrally closed, we need the following theorem. Let be the total quotient ring of , that is, the ring of germs of meromorphic functions.
Theorem.
Let be a local complex analytic variety. Then is the integralclosure of in
References
- 1 Hassler Whitney..Addison-Wesley, Philippines, 1972.