Article Dans Une Revue EPL - Europhysics Letters Année : 2009

Unveiling the nature of out-of-equilibrium phase transitions in a system with long-range interactions

Résumé

Recently, there has been some vigorous interest in the out-of-equilibrium quasistationary states (QSSs), with lifetimes diverging with the number N of degrees of freedom, emerging from numerical simulations of the ferromagnetic XY Hamiltonian Mean Field (HMF) starting from some special initial conditions. Phase transitions have been reported between low-energy magnetized QSSs and large-energy unexpected, antiferromagnetic-like, QSSs with low magnetization. This issue is addressed here in the Vlasov N→∞ limit. It is argued that the time-asymptotic states emerging in the Vlasov limit can be related to simple generic time-asymptotic forms for the force field. The proposed picture unveils the nature of the out-of-equilibrium phase transitions reported for the ferromagnetic HMF: this is a bifurcation point connecting an effective integrable Vlasov one-particle time-asymptotic dynamics to a partly ergodic one which means a brutal open-up of the Vlasov one-particle phase space. Illustration is given by investigating the time-asymptotic value of the magnetization at the phase transition, under the assumption of a sufficiently rapid time-asymptotic decay of the transient force field.

Dates et versions

hal-01551016 , version 1 (29-06-2017)

Identifiants

Citer

Marie-Christine Firpo. Unveiling the nature of out-of-equilibrium phase transitions in a system with long-range interactions. EPL - Europhysics Letters, 2009, 88, pp.30010. ⟨10.1209/0295-5075/88/30010⟩. ⟨hal-01551016⟩
141 Consultations
0 Téléchargements

Altmetric

Partager

  • More