  In this paper automorphic motives are constructed and analyzed with a view
toward the understanding of the geometry of compactification manifolds in
string theory in terms of the modular structure of the worldsheet theory. The
results described generalize a framework considered previously in two ways,
first by relaxing the restriction to modular forms, and second by extending the
construction of motives from diagonal varieties to nondiagonal spaces. The
framework of automorphic forms and representations is described with a view
toward applications, emphasizing the explicit structure of these objects.
