Extremal Symplectic Lattices

J.R. Quine, P.L. Zhang

We study the Jacobian of the Picard curve and the Fermat curve with respect to the problem of maximizing the minimum non-zero norm. We use criteria for symplectic lattices related to the criteria of perfect and eutactic for classical lattices. We show that the Picard curve is a local maximum, but the Fermat curve is not.