Physica D: Nonlinear Phenomena最新文献_第3页

On a family of Poisson brackets on glncompatible with the Sklyanin bracket 关于与Sklyanin括号不相容的泊松括号族

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-16 DOI: 10.1016/j.physd.2025.134943

Vladimir V. Sokolov , Dmitry V. Talalaev

引用次数: 0

Improved polynomial rates of memory loss for nonstationary intermittent dynamical systems 改进的非平稳间歇动力系统的多项式记忆丢失率

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-16 DOI: 10.1016/j.physd.2025.134939

A. Korepanov , J. Leppänen

引用次数: 0

Local and global analysis of the displacement map for some near integrable systems 一类近可积系统位移图的局部和全局分析

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-15 DOI: 10.1016/j.physd.2025.134932

Francisco Braun , Leonardo Pereira Costa da Cruz , Joan Torregrosa

{"title":"Local and global analysis of the displacement map for some near integrable systems","authors":"Francisco Braun , Leonardo Pereira Costa da Cruz , Joan Torregrosa","doi":"10.1016/j.physd.2025.134932","DOIUrl":"10.1016/j.physd.2025.134932","url":null,"abstract":"<div><div>In this paper, we introduce an alternative method for applying averaging theory of orders 1 and 2 in the plane. This is done by combining Taylor expansions of the displacement map with the integral form of the Poincaré–Poyntriagin–Melnikov function. It is known that, to obtain results of order 2 with averaging theory, the first-order averaging function should be identically zero. However, when working with Taylor expansions of the <span><math><mi>i</mi></math></span>th-order averaging function, we usually cannot guarantee it is identically zero. We prove that the vanishing of certain coefficients of the Taylor series of the first-order averaging function ensures it is identically zero. We present our reasoning in several concrete examples: a quadratic Lotka–Volterra system, a quadratic Hamiltonian system, the entire family of quadratic isochronous differential systems, and a cubic system. For the latter, we also show that a previous analysis contained in the literature is not correct. In none of the examples is it necessary to precisely calculate the averaging functions.</div></div>","PeriodicalId":20050,"journal":{"name":"Physica D: Nonlinear Phenomena","volume":"483 ","pages":"Article 134932"},"PeriodicalIF":2.9,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

On the complete integrability of space–time shifted nonlocal equations 时空位移非局部方程的完全可积性

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-13 DOI: 10.1016/j.physd.2025.134931

Baoqiang Xia

引用次数: 0

Existence of wave trains to mass-in-mass lattices 质量中质量晶格的波列的存在性

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-13 DOI: 10.1016/j.physd.2025.134918

Ling Zhang , Zhisu Liu

引用次数: 0

Flexible evolution of flocking tracking for a nonlinear collective migration model with heterogeneous transmission delays 具有异构传输延迟的非线性群体迁移模型的柔性演化

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-12 DOI: 10.1016/j.physd.2025.134927

Yipeng Chen, Yicheng Liu, Xiao Wang

{"title":"Flexible evolution of flocking tracking for a nonlinear collective migration model with heterogeneous transmission delays","authors":"Yipeng Chen, Yicheng Liu, Xiao Wang","doi":"10.1016/j.physd.2025.134927","DOIUrl":"10.1016/j.physd.2025.134927","url":null,"abstract":"<div><div>Division of labour and cooperation in animal groups is an external manifestation of swarm intelligence, such as leaders and followers in collective migration of animals. In this paper, we propose a nonlinear multi-agent system named collective migration model and try to build a more realistic dynamic leader–follower structure that facilitates flexible evolution of flocking tracking. The model highlights individual heterogeneity, especially including heterogeneous transmission delays among agents and heterogeneous parameters called tracking strategies that establish a trade-off between alignment and tracking for each agent, and essentially determine the leader–follower structure of the system. By constructing dynamic upper bounds of velocity, setting tracking periods and partitioning state space, a time-varying tracking strategy vector is designed to produce a dynamic leader–follower structure in which the system has a flexible configuration and can achieve flocking tracking for any initial state. The increase of transmission delay prolongs the switching cycle of leader–follower structure, and decreases the convergence speed of the system. An algorithm of the tracking strategy vector and several numerical simulations are provided to verify our results.</div></div>","PeriodicalId":20050,"journal":{"name":"Physica D: Nonlinear Phenomena","volume":"483 ","pages":"Article 134927"},"PeriodicalIF":2.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Whirling hexagonal convection in a rotating binary-alloy mushy layer 旋转二元合金糊状层中的旋转六角形对流

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-11 DOI: 10.1016/j.physd.2025.134897

Miloš Revallo , Peter Guba

引用次数: 0

Organized structures and different types of multistability in a one-dimensional ecological model — A parameter plane study 一维生态模型中有组织结构和不同类型的多稳定性——一个参数平面研究

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-10 DOI: 10.1016/j.physd.2025.134908

Ruma Kumbhakar, Nikhil Pal

{"title":"Organized structures and different types of multistability in a one-dimensional ecological model — A parameter plane study","authors":"Ruma Kumbhakar, Nikhil Pal","doi":"10.1016/j.physd.2025.134908","DOIUrl":"10.1016/j.physd.2025.134908","url":null,"abstract":"<div><div>In this article, we present an in-depth investigation of the parameter plane of a one-dimensional ecological model, highlighting the existence of intriguing dynamical scenarios and organized structures even in a rather simple ecological model. Specifically, we report the discovery of a fish-like periodic structure with period one surrounded by an unbounded region and numerous shrimp-shaped structures for the first time within the parameter plane of a one-dimensional ecological map. We uncover diverse dynamical phases in the parameter plane using isoperiodic diagrams and Lyapunov exponent diagrams. Our analyses reveal both period-doubling and period-bubbling cascades. We also observe the prevalence of various types of homogeneous and heterogeneous multistability phenomena. The most notable finding of the present study is the emergence of chaos–chaos multistability, characterized by the coexistence of two distinct chaotic attractors. Additionally, we identify a qualitatively different form of chaotic behavior referred to as multi-state intermittency, in which trajectories switch intermittently between two distinct fixed points rather than settling around a single fixed point. The insights gained from this study will significantly improve the understanding of complex and nuanced dynamical scenarios present in the parameter plane of one-dimensional ecological models, and provide a foundation for exploring and visualizing similar dynamical scenarios in higher-dimensional ecological models.</div></div>","PeriodicalId":20050,"journal":{"name":"Physica D: Nonlinear Phenomena","volume":"483 ","pages":"Article 134908"},"PeriodicalIF":2.9,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Guaranteed stable quadratic models and their applications in SINDy and operator inference 保证稳定二次模型及其在SINDy和算子推理中的应用

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-10 DOI: 10.1016/j.physd.2025.134893

Pawan Goyal , Igor Pontes Duff , Peter Benner

{"title":"Guaranteed stable quadratic models and their applications in SINDy and operator inference","authors":"Pawan Goyal , Igor Pontes Duff , Peter Benner","doi":"10.1016/j.physd.2025.134893","DOIUrl":"10.1016/j.physd.2025.134893","url":null,"abstract":"<div><div>Scientific machine learning for inferring dynamical systems combines data-driven modeling, physics-based modeling, and empirical knowledge. It plays an essential role in engineering design and digital twinning. In this work, we primarily focus on an <em>operator inference</em> methodology that builds dynamical models, preferably in low dimensions, with a prior hypothesis on the model structure, often determined by known physics or given by experts. Then, for inference, we aim to learn the operators of a model by setting up an appropriate optimization problem. One of the critical properties of dynamical systems is <em>stability</em>. However, this property is not guaranteed by the inferred models. In this work, we propose inference formulations to learn quadratic models, which are stable by design. Precisely, we discuss the parameterization of quadratic systems that are locally and globally stable. Moreover, for quadratic systems with no stable point yet bounded (e.g., chaotic Lorenz model), we discuss how to parameterize such bounded behaviors in the learning process. Using those parameterizations, we set up inference problems, which are then solved using a gradient-based optimization method. Furthermore, to avoid numerical derivatives and still learn continuous systems, we make use of an integral form of differential equations. We present several numerical examples, illustrating the preservation of stability and discussing its comparison with the existing state-of-the-art approaches to infer operators. By means of numerical examples, we also demonstrate how the proposed methods are employed to discover governing equations and energy-preserving models.</div></div>","PeriodicalId":20050,"journal":{"name":"Physica D: Nonlinear Phenomena","volume":"483 ","pages":"Article 134893"},"PeriodicalIF":2.9,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

IF 2.9 3区数学

Physica D: Nonlinear Phenomena Pub Date : 2025-09-08 DOI: 10.1016/j.physd.2025.134924

Manohar Teja Kalluri, Andrew Hillier

{"title":"Self-similarity and growth of non-linear magnetic Rayleigh–Taylor instability — Role of the magnetic field strength","authors":"Manohar Teja Kalluri, Andrew Hillier","doi":"10.1016/j.physd.2025.134924","DOIUrl":"10.1016/j.physd.2025.134924","url":null,"abstract":"<div><div>The non-linear regime of the magnetic Rayleigh–Taylor instability (MRTI) has been studied in the context of several laboratory and astrophysical systems. Yet, several fundamental aspects remain unclear. One of them is the self-similar evolution of the instability. Studies have assumed that non-linear MRTI has a self-similar, quadratic growth similar to hydrodynamic (HD) RTI. However, neither self-similarity nor quadratic growth has been proved analytically. Furthermore, an explicit understanding of the factors that control the growth of non-linear instability remains unclear. Magnetic fields are known to play a crucial role in the evolution of the instability. Yet, a systematic study discussing how the magnetic field influences the instability growth is missing. These issues were addressed by performing an analytical and numerical study of the MRTI with a uniform magnetic field. Our study reveals that the imposed magnetic field does not conform to the HD self-similar evolution. However, the influence of the imposed magnetic field decays with time (<span><math><mi>t</mi></math></span>) as <span><math><mrow><mn>1</mn><mo>/</mo><mi>t</mi></mrow></math></span> relative to the other non-linear terms, making the MRTI conform to the HD self-similarity. Thus, the HD RTI self-similar scaling becomes relevant to MRTI at late times, when nonlinear dynamics dominate. Based on energy conservation, an equation for the mixing layer height (<span><math><mi>h</mi></math></span>) is derived, which demonstrates the quadratic growth of <span><math><mi>h</mi></math></span> in time. This gave insight into various factors that could influence the non-linear growth of the instability. By studying MRTI at different magnetic field strengths, we demonstrate the role of magnetic field strength on the nonlinear growth of MRTI. Thus, the current study analytically and numerically proves the role of magnetic fields on the evolution of MRTI.</div></div>","PeriodicalId":20050,"journal":{"name":"Physica D: Nonlinear Phenomena","volume":"483 ","pages":"Article 134924"},"PeriodicalIF":2.9,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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