  Moduli with flat or run-away classical potentials are generic in theories
based on supersymmetry and extra dimensions. They mix between themselves and
with matter fields in kinetic terms and in the nonperturbative superpotentials.
As the result, interesting structure appears in the scalar potential which
helps to stabilise and trap moduli and leads to multi-field inflation. The new
and attractive feature of multi-inflationary setup are isocurvature
perturbations which can modify in an interesting way the final spectrum of
primordial fluctuations resulting from inflation.

High Energy Physics - Theory