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Updated: Jun 19, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Out-of-equilibrium phase re-entrance(s) in long-range interacting systems
F Staniscia1, P H Chavanis, G De Ninno
1Dipartimento di Fisica, Università di Trieste, 34127 Trieste, Italy.
Summary
Long-range interacting systems exhibit quasistationary states (QSSs). Lynden-Bell
Area of Science:
- Statistical Mechanics
- Nonequilibrium Systems
- Phase Transitions
Background:
- Systems with long-range interactions relax to quasistationary states (QSSs).
- QSS lifetime scales with system size.
- Lynden-Bell's theory describes 'violent relaxation' in such systems.
Purpose of the Study:
- Investigate phase transitions in the Hamiltonian Mean Field (HMF) model using Lynden-Bell's theory.
- Compare theoretical predictions with N-body simulations.
- Explore complex phenomena like phase re-entrance and negative specific heat.
Main Methods:
- Application of Lynden-Bell's theory to the HMF model.
- Direct N-body numerical simulations.
- Analysis of caloric curves for QSSs.
Main Results:
- Confirmed phase re-entrance in HMF model QSSs.
- Discovered secondary re-entrant phases: unmagnetized states in magnetized regions and vice-versa.
- Identified a region with negative specific heats in both numerical and analytical caloric curves.
Conclusions:
- Lynden-Bell's theory provides a framework for understanding QSS phase transitions, but the reality is more complex.
- Secondary re-entrant phases and negative specific heat regions are significant findings in HMF model dynamics.
- Further research is needed to fully elucidate the behavior of systems with long-range interactions.
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