On the generalised Kummer fourfold of the Jacobian of a genus two curve

We construct a birational model of the generalised Kummer fourfold of the Jacobian of a genus two curve, based on a geometric interpretation of the addition law on this Jacobian, obtained by the properties of the linear system of cubics on that curve. We show that our model has mild singularities and that it admits a finite ramified covering to the four-dimensional projective space.