Up to isomorphism, every three-dimensional simple principally polarized abelian variety
over
is the Jacobian of a smooth projective curve of genus 3. Furthermore, this curve is
either a hyperelliptic curve or a plane quartic. To define hyperelliptic class
polynomials, we note that given a hyperelliptic Jacobian with CM, all principally
polarized abelian varieties that are Galois conjugated to it are hyperelliptic. Using
Shimura’s reciprocity law, we then compute approximations of the invariants of the
initial curve, as well as their Galois conjugates. We show examples of class
polynomials computed using this method for the Shioda and Rosenhain
invariants.
Keywords
hyperelliptic curve, complex multiplication, theta
constants, class field