Relaxation Dynamics of Integrable Field Theories

We investigate the time evolution of one-point functions in integrable field theories after a global quantum quench is performed: this protocol consists of a non-adiabatic (i.e. instantaneous) change of the coupling constants that govern the Hamiltonian. We fully determine the time evolution of one-point functions and show how the characteristics of the considered observable lead to substantially different outcomes. In addition, these results allow us to compute the entanglement entropy of a bipartite system and link its growth in time to our main results.