After a brief review the theory of cosmological perturbations, I highlight
some recent progress in the area of reheating in inflationary cosmology, fo
cusing in particular on parametric amplification of super-Hubble cosmologic
al fluctuations, and on the role of noise in the resonance dynamics (yieldi
ng a new proof of Anderson localization). I then discuss several important
conceptual problems for the current realizations of inflation based on fund
amental scalar matter fields, and review some new approaches at solving the
se problems.