Jentsch Patrick, Lee Chiu Fan
Department of Bioengineering, <a href="https://ror.org/041kmwe10">Imperial College London</a>, South Kensington Campus, London SW7 2AZ, United Kingdom.
Phys Rev Lett. 2024 Sep 20;133(12):128301. doi: 10.1103/PhysRevLett.133.128301.
The Vicsek simulation model of flocking together with its theoretical treatment by Toner and Tu in 1995 were two foundational cornerstones of active matter physics. However, despite the field's tremendous progress, the actual universality class (UC) governing the scaling behavior of Viscek's "flocking" phase remains elusive. Here, we use nonperturbative, functional renormalization group methods to analyze, numerically and analytically, a simplified version of the Toner-Tu model, and uncover a novel UC with scaling exponents that agree remarkably well with the values obtained in a recent simulation study by Mahault et al. [Phys. Rev. Lett. 123, 218001 (2019)PRLTAO0031-900710.1103/PhysRevLett.123.218001], in both two and three spatial dimensions. We therefore believe that there is strong evidence that the UC uncovered here describes Vicsek's flocking phase.
维塞克群体运动模拟模型及其在1995年由托纳和图进行的理论处理是活性物质物理学的两个基础基石。然而，尽管该领域取得了巨大进展，但支配维塞克“群体运动”阶段标度行为的实际普适类（UC）仍然难以捉摸。在这里，我们使用非微扰的泛函重整化群方法，对托纳-图模型的一个简化版本进行数值和解析分析，并发现了一个新的普适类，其标度指数与马奥尔特等人[《物理评论快报》123, 218001 (2019年)PRLTAO0031 - 900710.1103/PhysRevLett.123.218001]最近的模拟研究中在二维和三维空间中获得的值非常吻合。因此，我们认为有强有力的证据表明这里发现的普适类描述了维塞克的群体运动阶段。
