论文标题
大偏差的集体运动
Collective motion in large deviations of active particles
论文作者
论文摘要
我们分析了在数值和分析的活动粒子系统中罕见（大偏差）事件中发生的集体运动。我们讨论了相关的动力学相变为集体运动的动力学转变，这是在主动工作偏向更大值的情况下发生的，并且与粒子方向的对齐有关。即使在大型系统中，也需要一个有限的偏置场来诱导自发对称性破坏。粒子比对完全针对两个粒子系统计算。对于许多颗粒系统，我们通过偏置动力学的最佳控制表示对称性破裂，并提出了一种波动的流体动力学理论，该理论捕获了偏向状态下极秩序的出现。
We analyse collective motion that occurs during rare (large deviation) events in systems of active particles, both numerically and analytically. We discuss the associated dynamical phase transition to collective motion, which occurs when the active work is biased towards larger values, and is associated with alignment of particles' orientations. A finite biasing field is needed to induce spontaneous symmetry breaking, even in large systems. Particle alignment is computed exactly for a system of two particles. For many-particle systems, we analyse the symmetry breaking by an optimal-control representation of the biased dynamics, and we propose a fluctuating hydrodynamic theory that captures the emergence of polar order in the biased state.
