SHIMURA CURVES AS INTERSECTIONS OF HUMBERT SURFACES AND DEFINING EQUATIONS OF QM-CURVES OF GENUS TWO

Abstract

Shimura curves classify isomorphism classes of abelian surfaces with quaternion multiplication. In this paper, we are concerned with a fibre space, the base space of which is a Shimura curve and fibres are curves of genus two whose jacobian varieties are abelian surfaces of the above type. We shall give an explicit defining equation for such a fibre space when the discriminant of the quaternion algebra is 6 or 10.