Paper 2, Section II, I
Part II, 2012
Let be the algebraic curve in defined by the polynomial where is a natural number. Using the implicit function theorem, or otherwise, show that there is a natural complex structure on . Let be the function defined by . Show that is holomorphic. Find the ramification points and the corresponding branching orders of .
Assume that extends to a holomorphic map from a compact Riemann surface to the Riemann sphere so that and that has no ramification points in . State the Riemann-Hurwitz formula and apply it to to calculate the Euler characteristic and the genus of .