Phase diagram of self-attracting systems

Area of Science:

• Statistical Mechanics
• Condensed Matter Physics
• Computational Physics

Background:

• Understanding phase transitions in systems with attractive interactions is crucial in physics.
• Self-attracting particles, such as self-gravitating fermions and classical particles with soft Coulomb potentials, present complex behaviors.
• Previous studies often relied on approximations that may not capture all relevant phenomena.

Purpose of the Study:

• To investigate the phase diagram of microcanonical ensembles for self-attracting particles.
• To analyze the effects of short-range potential regularization on phase transitions.
• To explore the crossover from gravitational to normal phase transitions and the role of critical points.

Main Methods:

• Studied microcanonical ensembles of self-attracting particles.
• Utilized two types of short-range potential regularizations: self-gravitating fermions and classical particles with soft Coulomb potentials.
• Analyzed the phase diagram by varying parameters like fermionic degeneracy and softness radius.

Main Results:

• Short-range regularization in self-attracting systems leads to gravitational or collapse-like transitions.
• Increasing fermionic degeneracy or softness radius causes a crossover from gravitational to first-order phase transitions.
• A critical point is identified where the transition becomes second-order before disappearing.

Conclusions:

• The study reveals a rich phase diagram for self-attracting particle systems with regularized interactions.
• The findings highlight the importance of potential regularization in determining the nature of phase transitions.
• The applicability of mean-field approximations and the significance of metastable states are discussed in this context.