论文标题
学习在有学到的新兴空间中学习新兴的PDE
Learning emergent PDEs in a learned emergent space
论文作者
论文摘要
我们从对大型耦合异质剂的动力学的观察结果中提取数据驱动的固有空间坐标。然后,这些坐标是一个新兴空间,在该空间中,以部分微分方程(PDE)的形式学习预测模型,以构成耦合代理系统的集体描述。它们在此PDE中起独立空间变量的作用(与因子(可能也是数据驱动的状态变量)相反)。这导致了对这些新兴坐标中局部动力学的替代描述,从而促进了复杂耦合代理系统的替代建模路径。我们在一个系统上说明了这种方法,在该系统中,每个代理都是极限周期振荡器(所谓的Stuart-Landau振荡器);代理是异质的(它们每个都有不同的固有频率$ω$),并且通过其各自变量的整体平均值结合。在快速初始瞬变之后,我们表明可以通过基于局部“空间”部分衍生物的局部模型近似慢速歧管上的集体动力学。然后将模型用于时间预测,并在系统参数变化时捕获集体分叉。因此,所提出的方法集成了出现空间的自动,数据驱动的提取,以参数为代理动力学,并在此参数化中对动力学的“新兴PDE”描述进行了辅助识别。
We extract data-driven, intrinsic spatial coordinates from observations of the dynamics of large systems of coupled heterogeneous agents. These coordinates then serve as an emergent space in which to learn predictive models in the form of partial differential equations (PDEs) for the collective description of the coupled-agent system. They play the role of the independent spatial variables in this PDE (as opposed to the dependent, possibly also data-driven, state variables). This leads to an alternative description of the dynamics, local in these emergent coordinates, thus facilitating an alternative modeling path for complex coupled-agent systems. We illustrate this approach on a system where each agent is a limit cycle oscillator (a so-called Stuart-Landau oscillator); the agents are heterogeneous (they each have a different intrinsic frequency $ω$) and are coupled through the ensemble average of their respective variables. After fast initial transients, we show that the collective dynamics on a slow manifold can be approximated through a learned model based on local "spatial" partial derivatives in the emergent coordinates. The model is then used for prediction in time, as well as to capture collective bifurcations when system parameters vary. The proposed approach thus integrates the automatic, data-driven extraction of emergent space coordinates parametrizing the agent dynamics, with machine-learning assisted identification of an "emergent PDE" description of the dynamics in this parametrization.