Vibrational spectra in glasses

The findings of X-ray and neutron scattering experiments on amorphous systems are interpreted within the framework of the theory of Euclidean random matrices. This allows us to take into account the topological nature of the disorder. a key ingredient which strongly affects the vibrational spectra of those systems. We present a resummation scheme for a perturbative expansion in the inverse particle density. allowing an accurate analytical computation of the dynamic structure factor within the range of densities encountered in real systems.