Level-two-structures and hyperelliptic curves
The author derives applications of his earlier work on graded rings of Siegel modular forms, theta constants and coding theory to geometry. In particular he uses several exceptional isomorphisms of subgroups of the symplectic groups to symmetric groups. This leads to some results on Specht modules. Moreover the geometry of the Igusa desingularization in genus 2 and level 2 is described. The coordinates are always theta constants. They are also used in order to obtain the equations of the Humbert surfaces in genus 2 and of the hyperelliptic points in genus 3.
scientific article; zbMATH DE number 1014603