论文标题
部分可观测时空混沌系统的无模型预测
Irreversiblity in Bacterial Turbulence: Insights from the Mean-Bacterial-Velocity Model
论文作者
论文摘要
我们使用平均细菌速度模型来研究二维（2d）\ textit {细菌湍流}的\ textit {不可逆性}，并将其与其2D流体扰动对应物进行比较。我们对该模型的速度场进行的拉格朗日示踪剂颗粒进行了广泛的直接数值模拟。 Our work uncovers an important, qualitative way in which irreversibility in bacterial turbulence is different from its fluid-turbulence counterpart: For large positive (or large but negative) values of the \textit{friction} (or \textit{activity}) parameter, the probability distribution functions of energy increments, along tracer trajectories, or the power are \textit{positively} skewed;因此，细菌湍流的不可逆性平均可能导致\ textit {粒子获得的能量比失去的能量更快}，这与2D流体湍流中示踪剂的观察到完全相反。
We use the mean-bacterial-velocity model to investigate the \textit{irreversibility} of two-dimensional (2D) \textit{bacterial turbulence} and to compare it with its 2D fluid-turbulence counterpart. We carry out extensive direct numerical simulations of Lagrangian tracer particles that are advected by the velocity field in this model. Our work uncovers an important, qualitative way in which irreversibility in bacterial turbulence is different from its fluid-turbulence counterpart: For large positive (or large but negative) values of the \textit{friction} (or \textit{activity}) parameter, the probability distribution functions of energy increments, along tracer trajectories, or the power are \textit{positively} skewed; so irreversibility in bacterial turbulence can lead, on average, to \textit{particles gaining energy faster than they lose it}, which is the exact opposite of what is observed for tracers in 2D fluid turbulence.
