Quantum Rolling Down out of Equilibrium

TL;DR

This paper investigates the out-of-equilibrium dynamics of a scalar field during a rapid phase transition, highlighting how quantum corrections and phase separation slow down the field's evolution.

Contribution

It introduces a novel analysis of the equations of motion from the one-loop effective action for slow rollover, emphasizing the impact of unstable fluctuations on dynamics.

Findings

Quantum corrections significantly alter the field's evolution.

Phase separation effects slow down the rollover process.

Unstable long-wavelength fluctuations dominate the dynamics.

Abstract

In a scalar field theory, when the tree level potential admits broken symmetry ground states, the quantum corrections to the static effective potential are complex. (The imaginary part is a consequence of an instability towards phase separation and the static effective potential is not a relevant quantity for understanding the dynamics). Instead, we study here the equations of motion obtained from the one loop effective action for slow rollover out of equilibrium. We considering the case in which a scalar field theory undergoes a rapid phase transition from $T_i>T_c$ to $T_f<T_c$. We find that, for slow rollover initial conditions (the field near the maximum of the tree level potential), the process of phase separation controlled by unstable long-wavelength fluctuations introduces dramatic corrections to the dynamical evolution of the field. We find that these effects slow the rollover even further