Chaté Hugues, Solon Alexandre
<a href="https://ror.org/0247p4w70">Service de Physique de l'Etat Condensé</a>, CEA, <a href="https://ror.org/03xjwb503">CNRS Université Paris-Saclay</a>, CEA-Saclay, 91191 Gif-sur-Yvette, France.
<a href="https://ror.org/04tavf782">Computational Science Research Center</a>, Beijing 100094, China.
Phys Rev Lett. 2024 Jun 28;132(26):268302. doi: 10.1103/PhysRevLett.132.268302.
We propose a hydrodynamic description of the homogeneous ordered phase of polar flocks. Starting from symmetry principles, we construct the appropriate equation for the dynamics of the Goldstone mode associated with the broken rotational symmetry. We then focus on the two-dimensional case considering both "Malthusian flocks" for which the density field is a fast variable that does not enter the hydrodynamic description and "Vicsek flocks" for which it does. In both cases, we argue in favor of scaling relations that allow one to compute exactly the scaling exponents, which are found in excellent agreement with previous simulations of the Vicsek model and with the numerical integration of our hydrodynamic equations.
我们提出了一种对极性群聚的均匀有序相的流体动力学描述。从对称性原理出发，我们构建了与破缺的旋转对称性相关的戈德斯通模式动力学的适当方程。然后我们专注于二维情况，考虑了两种情况：一种是“马尔萨斯群聚”，其密度场是一个快速变量，不进入流体动力学描述；另一种是“维塞克群聚”，其密度场会进入流体动力学描述。在这两种情况下，我们都支持缩放关系，这些关系使人们能够精确计算缩放指数，结果发现它们与维塞克模型之前的模拟以及我们流体动力学方程的数值积分结果非常吻合。
