Kaviya B, Gopal R, Suresh R, Chandrasekar V K
Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India.
Eur Phys J Plus. 2023;138(1):36. doi: 10.1140/epjp/s13360-022-03625-3. Epub 2023 Jan 17.
We explore the dynamics of a damped and driven Mathews-Lakshmanan oscillator type model with position-dependent mass term and report two distinct bifurcation routes to the advent of sudden, intermittent large-amplitude chaotic oscillations in the system. We characterize these infrequent and recurrent large oscillations as extreme events (EE) when they are significantly greater than the pre-defined threshold height. In the first bifurcation route, the system exhibits a bifurcation from quasiperiodic (QP) attractor to chaotic attractor via strange non-chaotic (SNA) attractor as a function of damping parameter. In the second route, the chaotic attractor in the form of EE has emerged directly from the QP attractor. Hence, to the best of our knowledge, this is the first study to report the birth of EE from these two distinct bifurcation routes. We also discuss that EE are emerged due to the sudden expansion of the chaotic attractor via interior crisis in the system. Regions of different dynamical states are distinguished using the Lyapunov exponent spectrum. Further, SNA and QP dynamics are determined using the singular spectrum analysis and 0-1 test. The region of EE is characterized using the threshold height.
我们研究了一个具有位置依赖质量项的阻尼驱动Mathews-Lakshmanan振子型模型的动力学，并报告了该系统中出现突然、间歇性大振幅混沌振荡的两种不同分岔路径。当这些罕见且反复出现的大振荡显著大于预先定义的阈值高度时，我们将其表征为极端事件（EE）。在第一条分岔路径中，系统随着阻尼参数的变化，通过奇异非混沌（SNA）吸引子从准周期（QP）吸引子分岔到混沌吸引子。在第二条路径中，以EE形式出现的混沌吸引子直接从QP吸引子中产生。因此，据我们所知，这是第一项报道从这两种不同分岔路径产生EE的研究。我们还讨论了EE是由于系统内部危机导致混沌吸引子突然扩张而出现的。使用李雅普诺夫指数谱区分不同动力学状态的区域。此外，使用奇异谱分析和0-1检验确定SNA和QP动力学。使用阈值高度表征EE区域。
