The moduli space of bilevel-6 abelian surfaces

Abstract

The moduli space of abelian surfaces with polarisation of type (1,6) and a bilevel structure has positive Kodaira dimension. By contrast, Mukai has shown that the moduli space of bilevel-t abelian sufaces is rational for t=2,3,4,5.Comment: 9 pages, plain TeX. Results improved and extended: an error correcte