### Abstract

Equilibrium and nonequilibrium studies of a hard point chain are performed under the condition of a vanishing external pressure. If all particles have the same mass, the dynamics is integrable, but the evolution is highly nontrivial. Numerical simulations in fact reveal that the particle velocities (which are integrals of motion) subdiffuse at equilibrium, while they superdiffuse in steady nonequilibrium regimes. This latter behaviour induces an anomalous thermal conductivity similar to that seen in standard ergodic models. The complexity of the dynamics can be traced back to a peculiar property of the hard point chain which acts as a velocity-dependent filter. Finally, an accurate study of a diatomic (ergodic) chain is performed, which reveals that the thermal conductivity diverges as N2/5 with the number N of particles. This analysis confirms the conjecture that one-dimensional systems belong to a different universality class when the thermodynamic pressure vanishes.

Original language | English |
---|---|

Article number | P03028 |

Number of pages | 12 |

Journal | Journal of statistical mechanics-Theory and experiment |

Volume | 2011 |

DOIs | |

Publication status | Published - Mar 2011 |

### Keywords

- heat conduction
- transport
- lattices

### Cite this

**Heat conduction of the hard point chain at zero pressure.** / Politi, Antonio.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - Heat conduction of the hard point chain at zero pressure

AU - Politi, Antonio

PY - 2011/3

Y1 - 2011/3

N2 - Equilibrium and nonequilibrium studies of a hard point chain are performed under the condition of a vanishing external pressure. If all particles have the same mass, the dynamics is integrable, but the evolution is highly nontrivial. Numerical simulations in fact reveal that the particle velocities (which are integrals of motion) subdiffuse at equilibrium, while they superdiffuse in steady nonequilibrium regimes. This latter behaviour induces an anomalous thermal conductivity similar to that seen in standard ergodic models. The complexity of the dynamics can be traced back to a peculiar property of the hard point chain which acts as a velocity-dependent filter. Finally, an accurate study of a diatomic (ergodic) chain is performed, which reveals that the thermal conductivity diverges as N2/5 with the number N of particles. This analysis confirms the conjecture that one-dimensional systems belong to a different universality class when the thermodynamic pressure vanishes.

AB - Equilibrium and nonequilibrium studies of a hard point chain are performed under the condition of a vanishing external pressure. If all particles have the same mass, the dynamics is integrable, but the evolution is highly nontrivial. Numerical simulations in fact reveal that the particle velocities (which are integrals of motion) subdiffuse at equilibrium, while they superdiffuse in steady nonequilibrium regimes. This latter behaviour induces an anomalous thermal conductivity similar to that seen in standard ergodic models. The complexity of the dynamics can be traced back to a peculiar property of the hard point chain which acts as a velocity-dependent filter. Finally, an accurate study of a diatomic (ergodic) chain is performed, which reveals that the thermal conductivity diverges as N2/5 with the number N of particles. This analysis confirms the conjecture that one-dimensional systems belong to a different universality class when the thermodynamic pressure vanishes.

KW - heat conduction

KW - transport

KW - lattices

U2 - 10.1088/1742-5468/2011/03/P03028

DO - 10.1088/1742-5468/2011/03/P03028

M3 - Article

VL - 2011

JO - Journal of statistical mechanics-Theory and experiment

JF - Journal of statistical mechanics-Theory and experiment

SN - 1742-5468

M1 - P03028

ER -