  The wave function of a non-relativistic particle in a periodic potential
admits oscillatory solutions, the Bloch waves. In the presence of a random
noise contribution to the potential the wave function is localized. We outline
a new proof of this Anderson localization phenomenon in one spatial dimension,
extending the classical result to the case of a periodic background potential.
The proof makes use of techniques previously developed to study the effects of
noise on reheating in inflationary cosmology, employing methods of random
matrix theory.
