Chaos最新文献_第7页

Locally repulsive coupling-induced tunable oscillations. 局部排斥耦合诱导的可调谐振荡。

IF 2.7 2区数学

Chaos Pub Date : 2025-01-01 DOI: 10.1063/5.0244771

Xiaoming Liang, Fan Mo, Qun Wang, Huaping Lü

引用次数: 0

Tipping events in a fear-affected symbiotic ecological system with adaptive hunting strategy.

IF 2.7 2区数学

Chaos Pub Date : 2025-01-01 DOI: 10.1063/5.0241236

Md Kausar Sk, Arindam Mandal, Joydev Chattopadhyay

{"title":"Tipping events in a fear-affected symbiotic ecological system with adaptive hunting strategy.","authors":"Md Kausar Sk, Arindam Mandal, Joydev Chattopadhyay","doi":"10.1063/5.0241236","DOIUrl":"https://doi.org/10.1063/5.0241236","url":null,"abstract":"Experimental observations and field data demonstrated that predators adapt their hunting strategies in response to prey abundance. While previous studies explored the impact of predation risk on predator-prey interactions, the impact of symbiotic relationships between fear-affected prey and non-prey species on system dynamics remains unexplored. This study uses a mathematical approach to investigate how different symbiotic relationships govern system dynamics when predators adapt to prey availability. Our study illustrates that the mutualistic relationship between prey and partners extends predator survivability. However, the fear-affected symbiotic system may undergo regime shifts, which can be catastrophic or non-catastrophic, depending on symbiotic interaction patterns. The study demonstrates a hump-shaped relationship between the predator's optimal search rate and biomass and identifies an intermediate range of search rates where the system exhibits a \"bubbling\"phenomenon. Overall, our findings provide new insights into symbiotic relationships in community ecology, highlighting the complex interplay among predators, prey, and non-prey species.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143051643","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

Singularity of Lévy walks in the lifted Pomeau-Manneville map.

IF 2.7 2区数学

Chaos Pub Date : 2025-01-01 DOI: 10.1063/5.0243549

Samuel Brevitt, Alexander Schulz, Dominic Pegler, Holger Kantz, Rainer Klages

{"title":"Singularity of Lévy walks in the lifted Pomeau-Manneville map.","authors":"Samuel Brevitt, Alexander Schulz, Dominic Pegler, Holger Kantz, Rainer Klages","doi":"10.1063/5.0243549","DOIUrl":"https://doi.org/10.1063/5.0243549","url":null,"abstract":"Since groundbreaking works in the 1980s it is well-known that simple deterministic dynamical systems can display intermittent dynamics and weak chaos leading to anomalous diffusion. A paradigmatic example is the Pomeau-Manneville (PM) map which, suitably lifted onto the whole real line, was shown to generate superdiffusion that can be reproduced by stochastic Lévy walks (LWs). Here, we report that this matching only holds for parameter values of the PM map that are of Lebesgue measure zero in its two-dimensional parameter space. This is due to a bifurcation scenario that the map exhibits under variation of one parameter. Constraining this parameter to specific singular values at which the map generates superdiffusion by varying the second one, as has been done in the previous literature, we find quantitative deviations between deterministic diffusion and diffusion generated by stochastic LWs in a particular range of parameter values, which cannot be cured by simple LW modifications. We also explore the effect of aging on superdiffusion in the PM map and show that this yields a profound change of the diffusive properties under variation of the aging time, which should be important for experiments. Our findings demonstrate that even in this simplest well-studied setting, a matching of deterministic and stochastic diffusive properties is non-trivial.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143051700","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

Interactions and asymptotic analysis of N-soliton solutions for the n-component generalized higher-order Sasa-Satsuma equations. n 分量广义高阶萨萨-萨妻方程的 N 索利子解的相互作用和渐近分析。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0237425

Zhuojie Lin, Zhenya Yan

引用次数: 0

Adaptive network approach to exploration-exploitation trade-off in reinforcement learning. 强化学习中探索-利用权衡的自适应网络方法。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0221833

Mohammadamin Moradi, Zheng-Meng Zhai, Shirin Panahi, Ying-Cheng Lai

{"title":"Adaptive network approach to exploration-exploitation trade-off in reinforcement learning.","authors":"Mohammadamin Moradi, Zheng-Meng Zhai, Shirin Panahi, Ying-Cheng Lai","doi":"10.1063/5.0221833","DOIUrl":"https://doi.org/10.1063/5.0221833","url":null,"abstract":"A foundational machine-learning architecture is reinforcement learning, where an outstanding problem is achieving an optimal balance between exploration and exploitation. Specifically, exploration enables the agents to discover optimal policies in unknown domains of the environment for gaining potentially large future rewards, while exploitation relies on the already acquired knowledge to maximize the immediate rewards. We articulate an approach to this problem, treating the dynamical process of reinforcement learning as a Markov decision process that can be modeled as a nondeterministic finite automaton and defining a subset of states in the automaton to represent the preference for exploring unknown domains of the environment. Exploration is prioritized by assigning higher transition probabilities to these states. We derive a mathematical framework to systematically balance exploration and exploitation by formulating it as a mixed integer programming (MIP) problem to optimize the agent's actions and maximize the discovery of novel preferential states. Solving the MIP problem provides a trade-off point between exploiting known states and exploring unexplored regions. We validate the framework computationally with a benchmark system and argue that the articulated automaton is effectively an adaptive network with a time-varying connection matrix, where the states in the automaton are nodes and the transitions among the states represent the edges. The network is adaptive because the transition probabilities evolve over time. The established connection between the adaptive automaton arising from reinforcement learning and the adaptive network opens the door to applying theories of complex dynamical networks to address frontier problems in machine learning and artificial intelligence.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"34 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766728","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

Strange nonchaotic attractor in an unforced turbulent reactive flow system. 非强迫湍流反应流系统中的奇异非混沌吸引子。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0233819

Beeraiah Thonti, Shruti Tandon, Premraj Durairaj, R I Sujith

引用次数: 0

Basin of attraction organization in infinite-dimensional delayed systems: A stochastic basin entropy approach. 无限维延迟系统中的吸引盆地组织：随机盆地熵方法。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0234028

Juan Pedro Tarigo, Cecilia Stari, Arturo C Martí

引用次数: 0

Bifurcations in the Kuramoto model with external forcing and higher-order interactions. 具有外部强迫和高阶相互作用的Kuramoto模型的分岔。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0239011

Guilherme S Costa, Marcel Novaes, Marcus A M de Aguiar

引用次数: 0

Arnold tongues, shrimp structures, multistability, and ecological paradoxes in a discrete-time predator-prey system. 阿诺德舌，虾结构，多稳定性，和离散时间捕食者-猎物系统的生态悖论。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0230994

Rajni, Bapan Ghosh

{"title":"Arnold tongues, shrimp structures, multistability, and ecological paradoxes in a discrete-time predator-prey system.","authors":"Rajni, Bapan Ghosh","doi":"10.1063/5.0230994","DOIUrl":"https://doi.org/10.1063/5.0230994","url":null,"abstract":"This paper explores a discrete-time system derived from the well-known continuous-time Rosenzweig-MacArthur model using the piecewise constant argument. Examining the impact of increasing carrying capacity and harvesting efforts, we uncover intricate phenomena, such as periodicity, quasiperiodicity, period-doubling, period-bubbling, and chaos. Our analysis reveals that increasing the carrying capacity of prey species can lead to both system stabilization and destabilization. We delve into normal forms associated with different bifurcation types, accompanied by numerical examples, observing multistabilities with intricate basin structures. Bistable, tristable, and quadruple attractors characterize the model's multistable states. Additionally, we find that enriching prey species negatively affects predator abundance, and increasing carrying capacity can lead to a sudden jump in predator population to the brink of extinction. Examining the two-parameter space of predator and prey harvesting efforts, we identify organized periodic structures: Arnold tongues and shrimp-like structures within quasiperiodic and chaotic regions. Arnold tongues exhibit a sequence of periodic adding. The shrimp structures indicate the existence of period-doubling and period-bubbling phenomena. Discussions on ecological interpretations of predator harvesting, including the paradoxical hydra effect, are provided.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"34 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766729","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

Self-organizing network representation of human heart. 人类心脏的自组织网络表示。

IF 2.7 2区数学

Chaos Pub Date : 2024-12-01 DOI: 10.1063/5.0243391

Runsang Liu, Hui Yang

引用次数: 0