Explicit CM-theory for level 2-structures on abelian surfaces

Reinier Broker, David Gruenewald, Kristin Lauter

For a complex abelian variety $A$ with endomorphism ring isomorphic to the maximal order in a quartic CM-field $K$, the Igusa invariants $j_1(A),j_2(A),j_3(A)$ generate an abelian…