Singular

D.15.21 hess_lib

Library:

hess.lib

Purpose:

Riemann-Roch space of divisors on function fields and curves

Authors:

I. Stenger: [email protected]

Overview:

Let f be an absolutely irreducible polynomial in two variables x,y. Assume that f is monic as a polynomial in y. Let F = Quot(k[x,y]/f) be the function field defined by f.
Define O_F = IntCl(k[x],F) and O_(F,inf) = IntCl(k[1/x],F). We represent a divisor D on F by two fractional ideals I and J of O_F and O_(F,inf), respectively. The Riemann-Roch space L(D) is then the intersection of I^(-1) and J^(-1).

Procedures:

D.15.21.1 RiemannRochHess

Computes a vector space basis of the Riemann-Roch space of a divisor