IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0247843

Róbert Juhász, Géza Ódor

{"title":"Finite-size scaling and dynamics in a two-dimensional lattice of identical oscillators with frustrated couplings.","authors":"Róbert Juhász, Géza Ódor","doi":"10.1063/5.0247843","DOIUrl":"https://doi.org/10.1063/5.0247843","url":null,"abstract":"A two-dimensional lattice of oscillators with identical (zero) intrinsic frequencies and Kuramoto type of interactions with randomly frustrated couplings is considered. Starting the time evolution from slightly perturbed synchronized states, we study numerically the relaxation properties, as well as properties at the stable fixed point which can also be viewed as a metastable state of the closely related XY spin glass model. According to our results, the order parameter at the stable fixed point shows generally a slow, reciprocal logarithmic convergence to its limiting value with the system size. The infinite-size limit is found to be close to zero for zero-centered Gaussian couplings, whereas, for a binary ±1 distribution with a sufficiently high concentration of positive couplings, it is significantly above zero. Besides, the relaxation time is found to grow algebraically with the system size. Thus, the order parameter in an infinite system approaches its limiting value inversely proportionally to ln⁡t at late times t, similarly to that found in the model with all-to-all couplings [Daido, Chaos 28, 045102 (2018)]. As opposed to the order parameter, the energy of the corresponding XY model is found to converge algebraically to its infinite-size limit.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143987523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The circular movement of synchronous extreme precipitation preceding Kerala floods in 2018 and 2019. 2018年和2019年喀拉拉邦洪水前同步极端降水的循环运动。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0246909

Praveenkumar Venkatesan, Gaurav Chopra, Rewanth Ravindran, Shraddha Gupta, Vishnu R Unni, Norbert Marwan, Jürgen Kurths, R I Sujith

{"title":"The circular movement of synchronous extreme precipitation preceding Kerala floods in 2018 and 2019.","authors":"Praveenkumar Venkatesan, Gaurav Chopra, Rewanth Ravindran, Shraddha Gupta, Vishnu R Unni, Norbert Marwan, Jürgen Kurths, R I Sujith","doi":"10.1063/5.0246909","DOIUrl":"https://doi.org/10.1063/5.0246909","url":null,"abstract":"In 2018 and 2019, Kerala, the southernmost state in India, experienced extreme precipitation, leading to appallingly devastating floods that damaged life and property. Kerala is vulnerable to flooding due to its topography, geographical location, and meteorology. Several phenomena have been attributed to these extreme precipitations; however, no single explanation suffices to explain such complex climate phenomena. We view the occurrence of extreme precipitation that leads to floods, such as an emerging phenomenon through the lens of complex system theory. We analyze the patterns of synchrony of extreme fluctuations in precipitation, outgoing longwave radiation, and water vapor transport. We construct time-varying functional climate networks, in which the statistical similarity between the time series of extreme precipitation at different spatial locations is estimated using event synchronization. The network topology reveals that excessive precipitation during the Kerala floods was associated with a coherent pattern of synchronized extreme rainfall. In the coherent phenomena discovered, the extreme rainfall was synchronized across a wide range of length scales spanning 100-1000 km. Furthermore, it traverses a synoptic scale path. After originating in the equatorial Indian Ocean, the coherent pattern moves eastward across the Bay of Bengal. The pattern stops over the Maritime Continent and changes its direction. It moves westward toward the Indian peninsula and accumulates over southwest India. We find that the extreme precipitation was driven by enhanced convective activity, leading to cloudiness and high-vapor transport in the atmosphere. Our findings improve the understanding of intraseasonal variability in the Indian monsoon and extreme precipitation events.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143969633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hamiltonian chaos for one particle with two waves: Self-consistent dynamics. 具有两波的一粒子的哈密顿混沌：自洽动力学。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0261013

Matheus J Lazarotto, Iberê L Caldas, Yves Elskens

引用次数: 0

In itinere infections covertly undermine localized epidemic control in metapopulations. 初期感染暗中破坏局部人群的流行病控制。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0275094

Francesca Dilisante, Pablo Valgañón, David Soriano-Paños, Jesús Gómez-Gardeñes

引用次数: 0

Geodesic vortex detection on curved surfaces: Analyzing the 2002 austral stratospheric polar vortex warming event. 曲面上的测地线涡旋探测：分析2002年南方平流层极地涡旋变暖事件。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0256314

F Andrade-Canto, F J Beron-Vera, G Bonner

{"title":"Geodesic vortex detection on curved surfaces: Analyzing the 2002 austral stratospheric polar vortex warming event.","authors":"F Andrade-Canto, F J Beron-Vera, G Bonner","doi":"10.1063/5.0256314","DOIUrl":"https://doi.org/10.1063/5.0256314","url":null,"abstract":"Geodesic vortex detection is a tool in nonlinear dynamical systems to objectively identify transient vortices with flow-invariant boundaries that defy the typical deformation found in 2D turbulence. Initially formulated for flows on the Euclidean plane with Cartesian coordinates, we have extended this technique to flows on 2D Riemannian manifolds with arbitrary coordinates. This extension required further formulation of the concept of objectivity on manifolds. Moreover, a recently proposed birth-and-death vortex framing algorithm, based on geodesic detection, has been adapted to address the limited temporal validity of 2D motion in otherwise 3D flows, like those found in the Earth's stratosphere. With these adaptations, we focused on the Lagrangian, i.e., kinematic, aspects of the austral stratospheric polar vortex during the exceptional sudden warming event of 2002, which resulted in the splitting of the vortex. This study involved applying geodesic vortex detection to isentropic winds from reanalysis data. We provide a detailed analysis of the vortex's life cycle, covering its birth, splitting process, and eventual death. In addition, we offer new kinematic insights into ozone depletion within the vortex.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143961211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Coherence resonance in a nonlinear aeroelastic system. 非线性气动弹性系统的相干共振。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0261296

Varun H S, M S Aswathy, Sunetra Sarkar

{"title":"Coherence resonance in a nonlinear aeroelastic system.","authors":"Varun H S, M S Aswathy, Sunetra Sarkar","doi":"10.1063/5.0261296","DOIUrl":"https://doi.org/10.1063/5.0261296","url":null,"abstract":"This study is a novel attempt to investigate and establish coherence resonance in a nonlinear aeroelastic system under additive Gaussian white noise. It offers a fresh perspective compared to the earlier studies in this field, which mostly focused on the undesirable disordered responses due to noise, while the present study explores the ability of noise to induce \"order\" in the system. The baseline deterministic model considered is a classical representative of a fluid-structure interaction system displaying subcritical Hopf bifurcation and is well-studied due to its engineering relevance. The interplay between the input noise and the nonlinearity has a profound impact on the dynamics, and at an optimum level of noise, the system exhibits nearly periodic, coherent oscillations. This is identified as the phenomenon of coherence resonance commonly exhibited by nonlinear systems, marked by a peak coherency in response at an intermediate noise level. The coherency is quantified by the signal-to-noise ratio, correlation time, and inter-spike intervals for conclusive evidence of the phenomenon. The effects of the findings could be far-reaching in aeroelasticity: noise could be used constructively to excite the desired coherent responses to increase the energy harvested from the structure, or conversely, trigger flutter instability which is detrimental to the structure.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Computing classical escape rates from periodic orbits in chaotic hydrogen. 计算混沌氢周期轨道的经典逃逸率。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0237613

Ethan T Custodio, Sulimon Sattari, Kevin A Mitchell

{"title":"Computing classical escape rates from periodic orbits in chaotic hydrogen.","authors":"Ethan T Custodio, Sulimon Sattari, Kevin A Mitchell","doi":"10.1063/5.0237613","DOIUrl":"https://doi.org/10.1063/5.0237613","url":null,"abstract":"When placed in parallel magnetic and electric fields, the electron trajectories of a classical hydrogen atom are chaotic. The classical escape rate of such a system can be computed with classical trajectory Monte Carlo techniques, but these computations require enormous numbers of trajectories, provide little understanding of the dynamical mechanisms involved, and must be completely rerun for any change of system parameters, no matter how small. We demonstrate an alternative technique to classical trajectory Monte Carlo computations based on classical periodic orbit theory. In this technique, escape rates are computed from a relatively modest number (a few thousand) of periodic orbits of the system. One only needs the orbits' periods and stability eigenvalues. A major advantage of this approach is that one does not need to repeat the entire analysis from scratch as system parameters are varied; one can numerically continue the periodic orbits instead. We demonstrate the periodic orbit technique for the ionization of a hydrogen atom in applied parallel electric and magnetic fields. Using fundamental theories of phase space geometry, we also show how to generate nontrivial symbolic dynamics for acquiring periodic orbits in physical systems. A detailed analysis of heteroclinic tangles and how they relate to bifurcations in periodic orbits is also presented.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A note on the coexistence of infinitely many attractors. 关于无穷多个吸引子共存的注解。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0272999

Xu Zhang, Mingtao Chen, Ran Zhang, Guanrong Chen

引用次数: 0

Excitable response of a noisy adaptive network of spiking lasers. 尖峰激光噪声自适应网络的可激响应。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0252964

S Barland, O D'Huys, R Veltz

引用次数: 0

Deriving production chains using restricted gradient extraction. 利用受限梯度提取法推导生产链。