We compute formal invariants associated with the cohomology sheaves of the
direct image of holonomic D-modules of exponential type. We also prove that
every formal C[[t]]-modules is isomorphic, after a ramification, to
a germ of formalized direct image of analytic D-module of exponential type.Comment: 19 pages, 5 figures, supported by a fellowship of the Deutsche
Forschungsgemeinschaft. Revised versio
