Space-time evolution of the \lap model: classical and quantum aspects

Abstract

A time dependent variational approach is used to derive the equations of motion for the \lambda \phi^4 model. The simultaneous evolution of the quantum fluctuations and of the classical part of the field is considered in a lattice of 1+1 dimensions. Different initial conditions corresponding to non equilibrium situations are considered and evolved in time. Such high energy localized configurations expand in the lattice by ``bumps'' which may change with time. The quantum fluctuations make the peaks be smoother and the expansion faster.