3rd International Conference on the Initial Stages in High-Energy Nuclear Collisions (InitialStages2016)

On the applicability of the Wigner functional approach to the description of far-from-equilibrium quantum fields.

Not scheduled

1m

Grande Anfiteatro (Centro de Congressos, Instituto Superior Técnico, Alameda Campus)

Poster Poster

Speaker

Anna Radovskaia (Russian Academy of Sciences (RU))

Description

We consider toy $\phi^4 $ -like model of quantum evolution of matter created at the early stages of ultrarelativistic heavy ion collisions.
With the aid of the Keldysh technique we derive systematic semiclassical expansion of the quantum field dynamics.
The Leading Order term of this expansion supports the well-known recipe for calculation of an observable -- averaging over initial conditions with weights given by Wigner function. However, applicability of the method can be tested only by calculation of the Next-to-Leading order corrections. We investigate the smallness of the Next-to-Leading order corrections for different parameters of the problem and reveal the range of applicability of the Wigner functional approach. We consider both cases of static and longitudinally expanding frameworks.