Vibrational anomalies and marginal stability of glasses Alessia Marruzzo, Stephan Köhler, Andrea Fratalocchi, Giancarlo Ruocco and Walter Schirmacher Eur. Phys. J. Special Topics, 216 (2013) 83-93 Published online: 31 January 2013 DOI: 10.1140/epjst/e2013-01731-5