Title: Escaping Cooperatively With Low Energies Speaker: Prof. Lutz Schimansky-Geier, Institut für Physik, Humboldt-Universität zu Berlin Time: Thursday, 14th May at 11:15 Coffee/tea and cake will be served at 11:05 Place: Room 1525-323 Abstract: We present the noise free escape of a chain of interacting units from a metastable state over a cubic potential barrier. The underlying dynamics is conservative and purely deterministic. Nonlinearity and harmonic interaction conspire such that the initially uniform lattice state becomes unstable leading to energy redistribution with strong localization. As a result a spontaneously emerging localized mode grows into the critical nucleus. By surpassing this transition state, the nonlinear chain manages a self-organized, deterministic barrier crossing. Most strikingly the noise-free, collective nonlinear escape events proceed by far faster than the transitions assisted by thermal noise. Particularly when the ratio between the average energy supplied per unit in the chain and the potential barrier energy assumes small values this enhancement of the rate of escape is of great avail. Alberto Imparato