论文标题
检测具有Crocker图的动态系统中的分叉
Detecting bifurcations in dynamical systems with CROCKER plots
论文作者
论文摘要
来自动态系统信号的分叉检测的现有工具通常仅限于特殊类别的系统,或者需要精心选择的输入参数,并且需要大量的专业知识来解释结果。因此,我们描述了一种基于持续的同源性(拓扑数据分析(TDA)的工具)的替代方法,该方法利用了Betti数字和Crocker图。 Betti数字是拓扑空间的拓扑不变性,而Crocker图是一个浓缩但易于可视化的一个参数变化的持久性条形码家族的数据表示形式。我们研究的特定分叉是从周期性到混乱行为的过渡,反之亦然,在一个参数的微分方程家族中。我们使用十个动态系统上的数值实验来验证我们的方法,并将结果与使用最大Lyapunov指数的现有工具进行对比。我们进一步证明了Wasserstein距离与空图的距离与Betti矢量的规范之间的关系,这表明该信息的更简化版本具有潜力,可以洞悉分叉参数。结果表明,我们的方法比标准工具揭示了有关周期性吸引子形状的更多信息,并且与Rosenstein算法相比,它具有更有利的计算时间,用于计算时间序列的Lyapunov指数。
Existing tools for bifurcation detection from signals of dynamical systems typically are either limited to a special class of systems, or they require carefully chosen input parameters, and significant expertise to interpret the results. Therefore, we describe an alternative method based on persistent homology -- a tool from Topological Data Analysis (TDA) -- that utilizes Betti numbers and CROCKER plots. Betti numbers are topological invariants of topological spaces, while the CROCKER plot is a coarsened but easy to visualize data representation of a one-parameter varying family of persistence barcodes. The specific bifurcations we investigate are transitions from periodic to chaotic behavior or vice versa in a one-parameter family of differential equations. We validate our methods using numerical experiments on ten dynamical systems and contrast the results with existing tools that use the maximum Lyapunov exponent. We further prove the relationship between the Wasserstein distance to the empty diagram and the norm of the Betti vector, which shows that an even more simplified version of the information has the potential to provide insight into the bifurcation parameter. The results show that our approach reveals more information about the shape of the periodic attractor than standard tools, and it has more favorable computational time in comparison to the Rosenstein algorithm for computing the Lyapunov exponent from time series.