HECKE CHARACTERS OF SINGULAR DRINFELD MODULES

The j-invariant j of a Drinfeld module of rank 2 on F-q[T] over C dete rmine an isomorphism class of Drinfeld modules over C. But for singula r Drinfeld modules the pair (j,chi) of a singular j-invariant j and an algebraic Hecke character chi represent an H-isomorphism class of sin gular Drinfeld modules, where H is the Hilbert class field of certain imaginary quadratic function field.