## Abstract / Description of output

We study flocking in one dimension, introducing a lattice model in which particles can move either left or right. We find that the model exhibits a continuous non-equilibrium phase transition from a condensed phase, in which a single 'flock' contains a finite fraction of the particles. to a homogeneous phase: we study the transition using numerical finite-size scaling. Surprisingly. in the condensed phase the steady state is alternating, with the mean direction of motion of particles reversing stochastically on a timescale proportional to the logarithm of the system size. We present a simple argument to explain this logarithmic dependence. We argue that the reversals are essential to the survival of the condensate. Thus, the discrete directional symmetry is not spontaneously broken.

Original language | English |
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Pages (from-to) | L99-L105 |

Number of pages | 7 |

Journal | Journal of Physics A: Mathematical and General |

Volume | 32 |

Issue number | 8 |

Publication status | Published - 26 Feb 1999 |

## Keywords / Materials (for Non-textual outputs)

- COLLECTIVE MOTION
- PHASE-TRANSITION
- PARTICLES
- SYSTEM