Extended Gibbs ensembles with flow.

Area of Science:

• Statistical mechanics
• Computational physics
• Condensed matter physics

Background:

• A novel statistical treatment for finite unbound systems with collective motion was recently proposed.
• This method addresses systems exhibiting collective dynamics, which are common in various physical phenomena.

Purpose of the Study:

• To apply a new statistical treatment to a classical Lennard-Jones system.
• To investigate the impact of flow dynamics on microstate distributions in expanding systems.

Main Methods:

• Molecular dynamics simulations were used to model a classical Lennard-Jones system.
• The proposed statistical treatment was adapted for low-density freeze-out configurations.
• Flow dynamics were analyzed within an ideal gas limit framework.

Main Results:

• In the ideal gas limit, flow dynamics were successfully recast into effective time-dependent Lagrange parameters.
• The statistical treatment was extended to interacting, expanding systems at low densities.
• The presence of flow was shown to significantly influence the microstate distribution.

Conclusions:

• The applied statistical method provides a robust framework for analyzing systems with collective motion.
• Flow dynamics play a crucial role in determining the microstate distribution of expanding systems.
• This work validates the statistical treatment for interacting, classical systems.