SP forthcoming seminar

[Cond.Matt. & Stat.Mech.Section]

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR



Tuesday, 2 February   -   11:00 hrs.





Lecture Room D - SISSA Main Building





Spyros SOTIRIADIS   (S.I.S.S.A.)





"Quantum quenches in interacting theories"



Abstract

The time evolution following a quantum quench, i.e. an instantaneous  
change in the parameters of an isolated quantum system, has been shown  
to lead, in a wide range of models and under quite general conditions,  
to stationary behaviour with some thermal characteristics.  After a  
review of free field theory results that introduces necessary new  
concepts and tools, we investigate a quantum quench in the phi^4 model  
in a self-consistent approximation.  A direct application of  
perturbation theory is not suitable in this case and resummation of  
Feynman diagrams is needed.  We propose an ansatz for the long time  
behaviour of the system, which we verify by a self-consistency  
calculation and numerical integration of the equations of motion.