论文标题
动力学和极地羊群的稳定状态随着出生和死亡
Kinetics and steady state of polar flock with birth and death
论文作者
论文摘要
我们研究了二维底物上的极性自propelled颗粒或极性植物的集合，并具有出生和死亡。先前关于出生和死亡的极性羊群的大多数研究都假设了可压缩的羊群，因此植物的局部密度完全忽略了。颗粒的出生和死亡对中等密度的羊群的影响是我们研究的重点。使用粗粒粒的运动方程进行系统建模，以用于植物的局部密度和速度，并使用非线性耦合部分运动的数值整合运动的运动和涉及对称状态的线性化流体动力学。我们研究了有限的出生和死亡率，研究了有序动力学以及不朽羊群和羊群的稳态特性。速度场的订购动力学仍然不受影响，而密度场显示不朽羊群的渐近生长指数$ 5/6 $的交叉，对于大生育和死亡率的扩散极限$ 1/3 $。在稳定状态下，出生和死亡速率的存在导致系统中声波和密度波动的速度抑制。
We study a collection of polar self-propelled particles or polar flock on a two dimensional substrate with birth and death. Most of the previous studies of polar flock with birth and death have assumed the compressible flock, such that the local density of flock is completely ignored. Effect of birth and death of particles on the flock with moderate density is focus of our study. System is modeled using coarse-grained hydrodynamic equations of motion for local density and velocity of the flock and solved using numerical integration of the nonlinear coupled partial differential equations of motion and linearised hydrodynamics about the broken symmetry state. We studied the ordering kinetics as well as the steady state properties of the immortal flock and flock with finite birth and death rate. The ordering kinetics of the velocity field remains unaffected whereas the density field shows a crossover from asymptotic growth exponent $5/6$ for the immortal flock to diffusive limit $1/3$ for large birth and death rates. In the steady state, the presence of birth and death rate leads to the suppression of speed of sound wave and density fluctuations in the system.
