# Impact of the initial fluctuations on the dissipative dynamics of interacting Fermi systems: A model case study

## TL;DR

This paper investigates how initial fluctuations influence the dissipative dynamics in interacting Fermi systems, demonstrating that non-Gaussian initial distributions improve long-term evolution predictions beyond traditional Gaussian assumptions.

## Contribution

It introduces a modification to the stochastic mean-field approach by relaxing the Gaussian assumption, enhancing the accuracy of long-time dissipative dynamics modeling.

## Key findings

- Non-Gaussian initial distributions reduce overdamping effects.
- Distributions with smaller kurtosis better reproduce long-term evolution.
- Gaussian assumptions tend to overestimate damping in the dynamics.

## Abstract

Standard methods used for computing the dynamics of a quantum many-body system are the mean-field (MF) approximations such as the time-dependent Hartree-Fock (TDHF) approach. Even though MF approaches are quite successful, they suffer some well-known shortcomings, one of which is insufficient dissipation of collective motion. The stochastic mean-field approach (SMF), where a set of MF trajectories with random initial conditions are considered, is a good candidate to include dissipative effects beyond mean field. In this approach, the one-body density matrix elements are treated initially as a set of stochastic Gaussian c numbers that are adjusted to reproduce first and second moments of collective one-body observables. It is shown that the predictive power of the SMF approach can be further improved by relaxing the Gaussian assumption for the initial probabilities. More precisely, using Gaussian or uniform distributions for the matrix elements generally leads to overdamping for long times, whereas distributions with smaller kurtosis lead to much better reproduction of the long time evolution.