2.II.23H

Riemann Surfaces
Part II, 2005

Define the terms function element and complete analytic function.

Let (f,D)(f, D) be a function element such that f(z)n=p(z)f(z)^{n}=p(z), for some integer n2n \geqslant 2, where p(z)p(z) is a complex polynomial with no multiple roots. Let FF be the complete analytic function containing (f,D)(f, D). Show that every function element (f~,D~)(\tilde{f}, \tilde{D}) in FF satisfies f~(z)n=p(z).\tilde{f}(z)^{n}=p(z) .

Describe how the non-singular complex algebraic curve

C={(z,w)C2wnp(z)=0}C=\left\{(z, w) \in \mathbb{C}^{2} \mid w^{n}-p(z)=0\right\}

can be made into a Riemann surface such that the first and second projections C2C\mathbb{C}^{2} \rightarrow \mathbb{C} define, by restriction, holomorphic maps f1,f2:CCf_{1}, f_{2}: C \rightarrow \mathbb{C}.

Explain briefly the relation between CC and the Riemann surface S(F)S(F) for the complete analytic function FF given earlier.

[You do not need to prove the Inverse Function Theorem, provided that you state it accurately.]