Hydrodynamics and phases of flocks

  title={Hydrodynamics and phases of flocks},
  author={John Toner and Yuhai Tu and S. N. Ramaswamy},
We review the past decade s theoretical and experimental studies of flocking: the collective, coherent motion of large numbers of self-propelled ‘‘particles’’ (usually, but not always, living organisms). Like equilibrium condensed matter systems, flocks exhibit distinct ‘‘phases’’ which can be classified by their symmetries. Indeed, the phases that have been theoretically studied to date each have exactly the same symmetry as some equilibrium phase (e.g., ferromagnets, liquid crystals). This… CONTINUE READING