Chaos Solitons & Fractals最新文献

{"title":"Conical diffraction and Floquet edge states in an electromagnetically induced Lieb lattice","authors":"Zijing Wang ,&nbsp;Sheng Xu ,&nbsp;ZhenkunWu ,&nbsp;Peng Li ,&nbsp;Feng Wen ,&nbsp;Yuzong Gu ,&nbsp;Yanbo Zhang","doi":"10.1016/j.chaos.2025.116423","DOIUrl":"10.1016/j.chaos.2025.116423","url":null,"abstract":"<div><div>we investigate conical diffraction and Floquet edge states in a Lieb photonic lattice induced in a Λ-type atomic system with electromagnetically induced transparency. By tuning frequency detuning and coupling field intensity, we demonstrate significant modifications to both the Bloch structure and the resulting diffraction patterns. Furthermore, we theoretically model a helical Floquet modulation to break time-reversal symmetry, resulting in a photonic topological insulator. Through detailed theoretical and numerical analyses, including calculations of Berry curvature and Chern numbers, we verify the emergence of unidirectional edge states and their robustness against defects. These findings highlight the potential for dynamically controlling beam propagation in atomic lattices and open promising avenues for designing advanced photonic devices with topological protection.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116423"},"PeriodicalIF":5.3,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143826453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slip temperature oscillation, turbulent magnetic-radiation and heat frequency effects on unsteady nanofluid along horizontal stretching circular cylinder: Darcy-Forchheimer nonlinear model","authors":"Zia Ullah ,&nbsp;Md. Mahbub Alam ,&nbsp;Asifa Ilyas ,&nbsp;Mohamed Ahmed Said ,&nbsp;Hanaa Abu-Zinadah ,&nbsp;M.D. Alsulami ,&nbsp;Hela Ahmad Gnaba ,&nbsp;Abdullah A. Faqihi","doi":"10.1016/j.chaos.2025.116432","DOIUrl":"10.1016/j.chaos.2025.116432","url":null,"abstract":"<div><div>Slip temperature oscillation, slip concentration, turbulent electromagnetic radiation and Brownian motion effects on transient stability of heat and mass transfer is objective of this research. The Darcy Forchheimer magnetic nanofluid flow along horizontal stationary stretching circular cylinder with thermal radiation effects is used. The purpose of this study is to analyze the steady heating rate, amplitude of mass rate, oscillating flow behavior of nanofluid, and periodic oscillation in skin friction. The transformed mathematical equations are derived by using dimensionless variables for thermo physical factors. The smooth and similar programing algorithm is developed in FORTRAN language (Lahey-95) by using primitive and oscillatory stokes transformations. The implicit finite-difference approach on primitive steady and oscillating model is applied with Gaussian elimination method numerically. The steady fluid velocity function and steady temperature-concentration functions are plotted for some physical parameters within defined boundary values. The steady results are again used to display the transient friction-rate, periodic heat-rate and oscillating mass-rate along α = π/4 and α = π/3 positions of horizontal stationary circular cylinder. This work based on specific rage of key parameters such as thermal-slip 0.1 ≤ σ₁ ≤ 1.0, concentration slip 0.1 ≤ σ₂ ≤ 1.5, heat generation 0.1 ≤ δ ≤ 7.0, radiation 1.0 ≤ R_d ≤ 10.0, Darcy number 0.1 ≤ <em>F</em>_<em>r</em> ≤ 2.0, thermophoresis 0.1 ≤ N_T ≤ 1.0, reaction rate 0.1 ≤ γ ≤ 1.0, and Prandtl 0.1 ≤ <em>Pr</em> ≤ 10.0. The increasing amplitude of velocity and temperature slip distribution grows well as diffusion-convection parameter and thermal radiation increases at both angles. The slip temperature and slip concentration grows significantly as convective parameter increases. It is noted that impact of thermophoresis and heat generation enhances the oscillations and amplitudes of mass and heat transmission along horizontal stationary circular cylinder as porous effect decreases. It is noted that the turbulence and time-mean fluctuation in skin friction increases as Darcy parameter increases. High amplitude in fluctuating heat transfer is depicted for large Prandtl values.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116432"},"PeriodicalIF":5.3,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143830101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamical analysis of a fractional-order epidemic weighted network model and its finite-time control","authors":"Na Liu ,&nbsp;Jia Wang ,&nbsp;Junwei Sun ,&nbsp;Chong Zhang ,&nbsp;Qixun Lan ,&nbsp;Wei Deng","doi":"10.1016/j.chaos.2025.116402","DOIUrl":"10.1016/j.chaos.2025.116402","url":null,"abstract":"<div><div>Infectious diseases pose a major threat to public health worldwide, often leading to serious social and economic damage. It is necessary to propose an effective control method to help the disease die out quickly. Given that the weight between nodes represents the intimacy of people, which seriously affects the spread of diseases, a fractional-order epidemic model based on weighted networks is proposed. The stability properties of the system’s equilibrium points are rigorously analyzed through the application of fractional-order Lyapunov stability theory. Furthermore, a finite-time controller is proposed for application in infectious disease management. Finite-time control facilitates rapid reduction of infection rates over short durations, thereby offering a potent instrument for responding to abrupt outbreaks. This control strategy not only substantially mitigates the adverse socioeconomic impacts of the epidemic but also expedites the system’s response time, enabling control measures to more rapidly adapt to the dynamic changes in the epidemic. Finally, the validity of theoretical results is verified by simulation.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116402"},"PeriodicalIF":5.3,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143830102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dark matter-wave bound soliton molecules and modulation stability for spin-1 Gross–Pitaevskii equations in Bose–Einstein condensates","authors":"Qing Qin,&nbsp;Li Li,&nbsp;Fajun Yu","doi":"10.1016/j.chaos.2025.116365","DOIUrl":"10.1016/j.chaos.2025.116365","url":null,"abstract":"<div><div>The non-autonomous dark soliton solutions of the spin-1 Gross–Pitaevskii equations with a parabola external potential are considered. The spin-1 Gross–Pitaevskii equations are transformed into the constant-coefficient (autonomous) three-component Gross–Pitaevskii (3-GP) equations by using the similarity transformation method, the dark soliton solutions of the autonomous 3-GP equations are generated by using the Hirota’s bilinear method. Then we investigate the modulation stability (MS) of the autonomous 3-GP equations and find the relation between <span><math><mi>Ω</mi></math></span> and <span><math><mi>κ</mi></math></span>. The regions of MS and modulation instability (MI) are distinguished, and the stable solitons from the MS region are derived by selecting specific parameters. Since the bright soliton solutions of the spin-1 Gross–Pitaevskii equations have been described in detail in the other literatures, here we focus on the dark soliton solutions. We obtain non-autonomous dark one-soliton, dark two-soliton and some novel forms of dark soliton solutions, such as “<span><math><mi>X</mi></math></span>-typed”, “<span><math><mi>Y</mi></math></span>-typed”, “<span><math><mi>S</mi></math></span>-typed” and “<span><math><mi>Ψ</mi></math></span>-typed” wave solutions and some soliton interactions of the spin-1 Gross–Pitaevskii equations. Some special dynamic behaviors of dark solitons of the spin-1 Gross–Pitaevskii equations with an external potential are obtained via selecting some free functions. These obtained non-autonomous dark soliton solutions can give some potential applications in Bose–Einstein condensates (BECs).</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116365"},"PeriodicalIF":5.3,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predator–prey dynamics in autonomous and nonautonomous settings: Impacts of anti-predator behavior, refuge, and additional food","authors":"Archana Ojha ,&nbsp;Sayan Mandal ,&nbsp;Ravikant Singh ,&nbsp;Nilesh Kumar Thakur ,&nbsp;Pankaj Kumar Tiwari","doi":"10.1016/j.chaos.2025.116409","DOIUrl":"10.1016/j.chaos.2025.116409","url":null,"abstract":"<div><div>Predator–prey interactions, shaped by anti-predator behaviors, refuge use, and resource availability, drive ecological dynamics and species evolution. This study presents autonomous and nonautonomous models to examine the effects of prey defense mechanisms and external food sources for predator populations. The autonomous model focuses on constant scenarios, while the nonautonomous model accounts for seasonal variations. Numerical results reveal the intricate roles of prey anti-predator behavior, refuge capacity, and external food sources in driving population dynamics. We identify parameter thresholds critical to the survival of middle predators, uncovering novel bistability phenomenon and multistability scenarios characterized by oscillatory coexistence and predator-free steady states. Saddle–node and homoclinic bifurcations illustrate the sensitivity of the system to minor changes in the parameter values, highlighting regime shifts between predator-dominated and predator-free states. Additionally, we observe “bubbling” phenomenon linked to reduced prey consumption rates by middle predators, further elucidating the system’s complexity. Seasonal perturbations of the parameters yield diverse behaviors, including periodic oscillation, bursting, and chaotic dynamics. Notably, chaotic dynamics emerge when refuge coefficients are varied, which is confirmed by a positive Lyapunov exponent. These findings emphasize the destabilizing impact of seasonal forcing, which can lead to the decline of middle predator population. Our results provide critical insights into the stability and resilience of food web interactions, offering valuable guidance for conservation strategies and ecosystem management under fluctuating environmental conditions.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116409"},"PeriodicalIF":5.3,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Decentralized Federated Learning model based on population mobility networks: A case study of the COVID-19 pandemic","authors":"Bo Guan ,&nbsp;Yuzhuo Ren ,&nbsp;Yongxin Zhang","doi":"10.1016/j.chaos.2025.116396","DOIUrl":"10.1016/j.chaos.2025.116396","url":null,"abstract":"<div><div>This study proposes a Decentralized Federated Learning(DFL) framework based on population mobility networks to address the prediction challenges in multi-node dynamic systems. By incorporating an adjacency matrix constructed from population mobility networks, the framework ensures node independence while enabling dynamic information sharing and global collaborative optimization across nodes. Using the cumulative COVID-19 case predictions for 29 provinces, municipalities, and by using various provinces, autonomous regions, and municipalities in China as case studies, the performance of the column-randomized DFL model(CR-DFL) is systematically compared with that of the Isolated models(IS). Experimental results demonstrate that the CR-DFL model achieves significantly lower root mean square error (RMSE) than IS models in most nodes, with only three exceptions (Hebei, Tianjin, and Hubei) where the RMSE is slightly higher. Further analysis reveals that the CR-DFL model effectively captures complex dynamic relationships among nodes while accurately modeling global system dynamics. However, for certain nodes with unique dynamic characteristics, the prediction accuracy may be affected, indicating the need for further optimization to enhance robustness and adaptability. Additionally, this study explores potential directions for improvement, including optimizing communication efficiency, addressing data heterogeneity, and integrating multi-modal datasets.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116396"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AI-enhanced resilience in power systems: Adversarial deep learning for robust short-term voltage stability assessment under cyber-attacks","authors":"Yang Li ,&nbsp;Shitu Zhang ,&nbsp;Yuanzheng Li","doi":"10.1016/j.chaos.2025.116406","DOIUrl":"10.1016/j.chaos.2025.116406","url":null,"abstract":"<div><div>In the era of Industry 4.0, ensuring the resilience of cyber-physical systems against sophisticated cyber threats is increasingly critical. This study proposes a pioneering AI-based control framework that enhances short-term voltage stability assessments (STVSA) in power systems under complex composite cyber-attacks. First, by incorporating white-box and black-box adversarial attacks with Denial-of-Service (DoS) perturbations during training, composite adversarial attacks are implemented. Second, the application of Spectral Normalized Conditional Wasserstein Generative Adversarial Network with Gradient Penalty (SNCWGAN-GP) and Fast Gradient Sign Method (FGSM) strengthens the model's resistance to adversarial disturbances, improving data quality and training stability. Third, an assessment model based on Long Short-Term Memory (LSTM)-enhanced Graph Attention Network (L-GAT) is developed to capture dynamic relationships between the post-fault dynamic trajectories and electrical grid topology. Experimental results on the IEEE 39-bus test system demonstrate the efficacy and superiority of the proposed method in composite cyber-attack scenarios. This contribution is pivotal to advancing AI-based resilient control strategies for nonlinear dynamical systems, marking a substantial enhancement in the security of cyber-physical systems.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of predator–taxis and time delay on the dynamical behavior of a predator–prey model with prey refuge and predator harvesting","authors":"Yehu Lv","doi":"10.1016/j.chaos.2025.116388","DOIUrl":"10.1016/j.chaos.2025.116388","url":null,"abstract":"<div><div>In this paper, we consider a delay-driven population chemotaxis model with practical significance in biology, incorporating both prey refuge and predator harvesting terms. We first prove the local-in-time existence and uniqueness of classical solutions to this model for <span><math><mrow><mi>τ</mi><mo>=</mo><mn>0</mn></mrow></math></span>, and the global existence and uniqueness of classical solutions to this model for <span><math><mrow><mi>τ</mi><mo>&gt;</mo><mn>0</mn></mrow></math></span>. Then, using stability theory, bifurcation theory, and normal form theory, we analyze the local asymptotic stability of the positive constant steady state of the model, as well as the effects of predator chemotaxis and delay on the dynamics of the model. When the delay is zero, through rigorous mathematical analysis, we find that predator–taxis can induce a Turing bifurcation, and the combined effects of predator–taxis and random diffusion of the prey can trigger a Turing–Turing bifurcation. When the delay is nonzero, we show that the delay can induce a Hopf bifurcation, and the joint effects of predator–taxis and delay can result in Hopf–Hopf and Turing–Hopf bifurcations. Furthermore, we rigorously derive the third-order truncated normal form for the Hopf bifurcation of the model, which allows us to determine the direction of the Hopf bifurcation and the stability of the periodic solutions generated by the Hopf bifurcation. At the same time, numerical simulations are conducted to verify the results of the theoretical analysis.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116388"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and CFD evaluation of bubble diameter and turbulence model influence on nonlinear flow dynamics in vertical columns: A comparative study","authors":"Faisal Shah,&nbsp;Ibra Fall,&nbsp;Desheng Zhang","doi":"10.1016/j.chaos.2025.116421","DOIUrl":"10.1016/j.chaos.2025.116421","url":null,"abstract":"<div><div>This study examined the impact of a few numerical factors, such as mesh density, drag model selections, turbulence models, and bubble size descriptions on the numerical accuracy of gas-liquid (GL) flow. Multiphase flow in a vertical pipe with a diameter of 76.2 mm was simulated using the Eulerian-Eulerian (EE) model provided by ANSYS Fluent. A comparison with experimental findings shows that the two-phase flows are significantly impacted by the bubble size. To determine their effect on simulation accuracy, various kinds of turbulence models are assessed such as Standard <span><math><mi>k</mi><mo>−</mo></math></span>epsilon, RNG <span><math><mi>k</mi><mo>−</mo></math></span>epsilon and the Realizable <span><math><mi>k</mi><mo>−</mo></math></span>epsilon models. Four superficial gas velocities were used to investigate turbulence models where superficial liquid velocity is constant. Realizable <span><math><mi>k</mi><mo>−</mo></math></span>epsilon model often offers the closest fit to the experimental data. Particularly at high gas velocities and improved bubble sizes. This model often gives a more perfect interpretation of the void fraction and phase distribution than the other two models. Its improved performance implies that the Realizable <span><math><mi>k</mi><mo>−</mo></math></span>epsilon model is well managing anisotropy in the turbulence, enabling more precise predictions of the void percentage in intricate, extremely turbulent flow regimes. To enhance the precision of nonlinear flow predicts, future research should concentrate on investigating complex turbulence models and higher-order numerical schemes. Additionally, examining the effects of bubble coalescence, breakup dynamics, and three-dimensional flow effects would allow for a deeper comprehension of flow behaviour in vertical columns.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116421"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulse-coupled oscillator synchronization: Bridging theory and experiments with electronic firefly networks","authors":"Moisés Santillán","doi":"10.1016/j.chaos.2025.116377","DOIUrl":"10.1016/j.chaos.2025.116377","url":null,"abstract":"<div><div>While continuous coupled oscillator models, such as the Kuramoto model, have been extensively investigated, a comprehensive framework for understanding synchronization in pulse-coupled oscillator networks remains absent. In this study, we address this gap by integrating experimental and theoretical approaches. We explore synchronization dynamics through an electronic firefly system, revealing how external illumination disrupts synchronization beyond a critical threshold and affects the process of returning to synchronized states. We propose a minimal mathematical model inspired by laser theory, capturing the delicate balance between synchronizing and desynchronizing forces. Through bifurcation analysis, we identify a range of synchronization regimes – including complete synchronization, partial synchronization, bistability, and explosive synchronization – thereby elucidating the impact of model parameters on these behaviors. This research offers valuable insights into the mechanisms of synchronization in pulse-coupled systems and establishes a theoretical framework that may extend beyond the electronic firefly model, suggesting broader applications in complex networks of oscillators.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}