论文标题
在实验耦合的逻辑图中观察分叉和滞后
Observation of bifurcations and hysteresis in experimentally coupled logistic maps
论文作者
论文摘要
最初,物流图作为人口增长的简化模型变得流行。尽管它显然很简单,但随着人口增长率的增加,地图表现出广泛的动力学,其中包括从周期性到混乱溶液的分叉级联反应。研究耦合图可以识别集体动力学(例如模式形成或磁滞)中的其他定性变化。特别是,滞后是不同吸引集的外观,当控制参数增加时,一个集合在减少时是一个多稳定区域。在这项工作中,我们介绍了一项有关几乎相同,耦合,逻辑图的分叉和滞后的实验研究。我们的逻辑图是一个具有离散时间演化的电子系统,具有较高的信噪比($ \ sim10^6 $),导致简单,精确且可靠的实验操作,其中包括设计可修改的扩散耦合配置电路的设计。我们发现,孤立和耦合的逻辑映射动力学的特征与理论和数值预测非常吻合(例如关键分叉点以及Feigenbaum的分叉速度)。在这里,我们报告了跨配置的多稳定区域,即使我们的配置具有参数不匹配(我们直接从电路的组件直接测量,也从每个地图的结果动力学中推断出来,并且不可避免地会受到电子噪声的影响。
Initially, the logistic map became popular as a simplified model for population growth. In spite of its apparent simplicity, as the population growth-rate is increased the map exhibits a broad range of dynamics, which include bifurcation cascades going from periodic to chaotic solutions. Studying coupled maps allows to identify other qualitative changes in the collective dynamics, such as pattern formations or hysteresis. Particularly, hysteresis is the appearance of different attracting sets, a set when the control parameter is increased and another set when it is decreased -- a multi-stable region. In this work, we present an experimental study on the bifurcations and hysteresis of nearly identical, coupled, logistic maps. Our logistic maps are an electronic system that has a discrete-time evolution with a high signal-to-noise ratio ($\sim10^6$), resulting in simple, precise, and reliable experimental manipulations, which include the design of a modifiable diffusive coupling configuration circuit. We find that the characterisations of the isolated and coupled logistic-maps' dynamics agrees excellently with the theoretical and numerical predictions (such as the critical bifurcation points and Feigenbaum's bifurcation velocity). Here, we report multi-stable regions appearing robustly across configurations, even though our configurations had parameter mismatch (which we measure directly from the components of the circuit and also infer from the resultant dynamics for each map) and were unavoidably affected by electronic noise.