{"title":"Solvability, stability and its application in the P–M synchronization problem of discrete-time fractional order singular systems","authors":"Duong Thi Hong , Do Duc Thuan","doi":"10.1016/j.cnsns.2025.109175","DOIUrl":"10.1016/j.cnsns.2025.109175","url":null,"abstract":"<div><div>Fractional order singular systems are an important class of systems characterized by algebraic constraints combined with fractional-order dynamic behaviors. This paper focuses on discrete-time fractional order singular systems (DFOSSs), introducing the concept of the index to analyze their structural properties. Using the Drazin inverse, we establish a lemma that decomposes DFOSSs into simpler subsystems, forming the basis for deriving solvability and stability conditions. These results are achieved through techniques from fractional calculus and singular systems. Additionally, we provide an explicit solution formula for DFOSSs, enabling practical computation. A control strategy is then proposed to achieve <span><math><mrow><mi>P</mi><mtext>–</mtext><mi>M</mi></mrow></math></span> synchronization, a method that synchronizes different dimensions within the same master–slave system, surpassing traditional synchronization approaches. To demonstrate the utility of our findings, practical applications in electrical circuits are presented, showcasing the effectiveness of our methods. This study offers a comprehensive framework for analyzing and controlling DFOSSs, bridging theoretical insights with real-world applications.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109175"},"PeriodicalIF":3.8,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739271","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}
{"title":"The Riemann solutions of the Chaplygin Euler equations with discontinuity terms: The disappearance and generation of a delta shock wave","authors":"Zhijian Wei, Lihui Guo","doi":"10.1016/j.cnsns.2025.109170","DOIUrl":"10.1016/j.cnsns.2025.109170","url":null,"abstract":"<div><div>In this paper, the Riemann problems for Euler equations with the Chaplygin gas under two different discontinuity source terms are considered in detail. Four kinds of Riemann solutions are constructed in fully explicit forms by the contact discontinuity or the delta shock wave. Different from previous studies with continuous source terms, some interesting nonlinear phenomena are found. For instance, the delta shock wave disappears completely and splits into two contact discontinuities in finite time.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109170"},"PeriodicalIF":3.8,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723772","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}
{"title":"Reduction of algebraic delay systems to state-dependent delay systems","authors":"Redouane Qesmi","doi":"10.1016/j.cnsns.2025.109174","DOIUrl":"10.1016/j.cnsns.2025.109174","url":null,"abstract":"<div><div>In this paper, we show that a general class of algebraic-delay systems of differential equations <span><span><span><math><mfenced><mrow><mtable><mtr><mtd><msup><mrow><mi>x</mi></mrow><mrow><mo>′</mo></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow><mo>=</mo><mi>f</mi><mfenced><mrow><mi>τ</mi><mfenced><mrow><mi>t</mi></mrow></mfenced><mo>,</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>t</mi></mrow></msub></mrow></mfenced><mo>,</mo><mspace></mspace></mtd></mtr><mtr><mtd><mi>h</mi><mfenced><mrow><mi>τ</mi><mfenced><mrow><mi>t</mi></mrow></mfenced><mo>,</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>t</mi></mrow></msub></mrow></mfenced><mo>=</mo><mn>0</mn><mo>,</mo><mspace></mspace></mtd></mtr></mtable></mrow></mfenced></math></span></span></span>where the delay <span><math><mrow><mi>τ</mi><mfenced><mrow><mi>t</mi></mrow></mfenced></mrow></math></span> is defined implicitly through the state history <span><math><mrow><msub><mrow><mi>x</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>,</mo></mrow></math></span> can be reduced to systems with state-dependent delay. The algebraic-delay framework covers a number of cases, including threshold-type delays and other implicitly defined mechanisms. This reduction enables the use of established theoretical tools from the study of state-dependent delay equations to analyze both the local and global dynamics of systems with algebraic delays. As an application, we present an SIRS epidemic model incorporating waning immunity and immune system boosting, and provide both quantitative and partial qualitative analysis of its dynamics.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109174"},"PeriodicalIF":3.8,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722102","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}
{"title":"Spot solutions to a neural field equation on oblate spheroids","authors":"Hiroshi Ishii , Riku Watanabe","doi":"10.1016/j.cnsns.2025.109172","DOIUrl":"10.1016/j.cnsns.2025.109172","url":null,"abstract":"<div><div>Understanding the dynamics of excitation patterns in neural fields is an important topic in neuroscience. Neural field equations are mathematical models that describe the excitation dynamics of interacting neurons to perform the theoretical analysis. Although many analyses of neural field equations focus on the effect of neuronal interactions on the flat surface, the geometric constraint of the dynamics is also an attractive topic when modeling organs such as the brain. This paper reports pattern dynamics in a neural field equation defined on spheroids as model curved surfaces. We treat spot solutions as localized patterns and discuss how the geometric properties of the curved surface change their properties. To analyze spot patterns on spheroids with small flattening, we first construct exact stationary spot solutions on the spherical surface and reveal their stability. We then extend the analysis to show the existence and stability of stationary spot solutions in the spheroidal case. One of our theoretical results is the derivation of a stability criterion for stationary spot solutions localized at poles on oblate spheroids. The criterion determines whether a spot solution remains at a pole or moves away. Finally, we conduct numerical simulations to discuss the dynamics of spot solutions with the insight of our theoretical predictions. Our results show that the dynamics of spot solutions depend on the curved surface and the coordination of neural interactions.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109172"},"PeriodicalIF":3.8,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723771","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}
Zhiyong Si , Puxuan Xu , Yunxia Wang , Hongwei Wang
{"title":"The modified characteristics FEMs for the incompressible vector potential MagnetoHydroDynamics system","authors":"Zhiyong Si , Puxuan Xu , Yunxia Wang , Hongwei Wang","doi":"10.1016/j.cnsns.2025.109150","DOIUrl":"10.1016/j.cnsns.2025.109150","url":null,"abstract":"<div><div>In this paper, we investigate the modified characteristics finite element methods (FEMs) for the two- and three-dimensional incompressible magnetohydrodynamics (MHD) system, formulated using a magnetic vector potential approach. Specifically, we express the magnetic induction <span><math><mi>B</mi></math></span> as <span><math><mrow><mi>B</mi><mo>=</mo><mo>∇</mo><mo>×</mo><mi>A</mi></mrow></math></span>, where <span><math><mi>A</mi></math></span> is the magnetic vector potential. Through a rigorous analysis of the time-discrete system, we strictly establish that the error between the numerical solution and the time-discrete solution remains bounded, independent of the time step size <span><math><mi>τ</mi></math></span>. Theoretical results, including unconditional stability and error estimates in both <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> and <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> norms, are presented. Additionally, numerical experiments are conducted to demonstrate the efficiency and accuracy of the proposed method, validating the theoretical findings.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109150"},"PeriodicalIF":3.8,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722104","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}
{"title":"The second type noncommutative KP and mKP equations with self-consistent sources and Miura transformation","authors":"Muhammad Kashif, Chunxia Li","doi":"10.1016/j.cnsns.2025.109159","DOIUrl":"10.1016/j.cnsns.2025.109159","url":null,"abstract":"<div><div>By employing the source generation procedure, the second type noncommutative KP equation with self-consistent sources (second type NC KPESCS) and the second type noncommutative modified KP equation with self-consistent sources (second type NC mKPESCS) are derived. Two classes of quasideterminant solutions are presented with direct verification by establishing general derivative formulas for each case. Subsequently, matrix solutions are constructed and illustrated for both the second type NC KPESCS and the second type NC mKPESCS. Additionally, the Miura transformation is established between the second type NC KPESCS and the second type NC mKPESCS. Finally, some useful quasideterminant identities are provided.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109159"},"PeriodicalIF":3.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713056","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}
{"title":"Dynamics of a nonlocal diffusive SIR epidemic model with nonlocal infection","authors":"Subir Dey, Tapan Kumar Kar","doi":"10.1016/j.cnsns.2025.109161","DOIUrl":"10.1016/j.cnsns.2025.109161","url":null,"abstract":"<div><div>Nonlocal diffusion offers a more realistic framework for modeling epidemic dynamics by capturing the movement of individuals across broader spatial regions. In this study, we develop a nonlocal diffusive SIR epidemic model incorporating nonlocal infection transmission, modeled via a convolution of a spatial kernel function with the infected population’s spatial distribution. Using semigroup theory, we establish the global well-posedness, compactness, and asymptotic smoothness of the semiflow generated by the system, ensuring the mathematical robustness of the model. A principal eigenvalue problem for a perturbed nonlocal diffusion operator is examined, and the existence of a positive eigenfunction corresponding to the principal eigenvalue is shown. This principal eigenvalue acts analogously to the basic reproduction number <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, serving as a threshold parameter. In particular, a globally stable disease-free equilibrium occurs when <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub><mo><</mo><mn>1</mn></mrow></math></span>, whereas a globally stable endemic equilibrium emerges when <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>></mo><mn>1</mn></mrow></math></span>. To analyze this, two scenarios are examined: (i) when susceptible individuals do not diffuse but infected individuals do, and (ii) when both diffuse. Numerical simulations show that wider spatial diffusion increases <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, thereby enhancing the potential for disease spread. Also, increasing the infection radius, based on the compact support of the spatial kernel, plays a key role in reducing infection spread, revealing key insights into spatial control strategies for epidemic containment.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109161"},"PeriodicalIF":3.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713536","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}
{"title":"Conservation laws of mean field games equations with time discounting","authors":"Roman Kozlov","doi":"10.1016/j.cnsns.2025.109157","DOIUrl":"10.1016/j.cnsns.2025.109157","url":null,"abstract":"<div><div>A recent study (Kozlov, 2025) analyzed mean field games (MFG) equations for conservation laws. The approach exploits the variational form of the MFG equations in the case of separable Hamiltonians. The Noether theorem can be used to derive conservation laws for variational differential equations with symmetries. Separable, state-independent Hamiltonians were examined in the case of a one-dimensional state space. This article extends that framework to incorporate exponential time discounting. Time discounting is often employed in economics, finance, ecology, behavioral studies, and other fields, where it is crucial for addressing problems spanning long time intervals. The article analyses the general case of the MFG equations with exponential time discounting for symmetries and conservation laws and finds exceptional cases leading to extensions of symmetries and conservation laws. The results demonstrate that time-discounted MFG equations exhibit substantially different symmetry and conservation properties compared to their non-discounted counterparts.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109157"},"PeriodicalIF":3.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713535","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}
Manuel Miranda, Pablo Moreno-Spiegelberg, Ernesto Estrada
{"title":"Heterogeneous consensus dynamics through reaction–diffusion models on graphs/networks","authors":"Manuel Miranda, Pablo Moreno-Spiegelberg, Ernesto Estrada","doi":"10.1016/j.cnsns.2025.109160","DOIUrl":"10.1016/j.cnsns.2025.109160","url":null,"abstract":"<div><div>Consensus protocols (linear and nonlinear) are extensively used for multi-agent systems to perform a wide variety of tasks. Its connections with diffusive models make a natural bridge between engineering and social/natural complex systems. These protocols give rise to conservative processes on the graphs representing the systems, and reach homogeneous (consensus) steady states. Here we develop a model that extends the concept of global consensus (diffusion) to dynamical processes which are nonconservative on the graphs, and reach bounded steady states, which are not necessarily a global consensus. That is, they allow heterogeneous steady states in which different subsets of agents can reach a consensus among them, which may be different from the ones reached by other groups. We prove some mathematical results indicating how the structure of the graphs representing the system determines the final states of the dynamics. Finally, we illustrate the applications of the model by considering a heterogeneous rendezvous of a group of agents, as well as the connections of the model with the Bass model for diffusion of innovation and the Lotka–Volterra equations to model the evolution of groups of species that interact in different ways.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109160"},"PeriodicalIF":3.8,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723884","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}
Yanan Li , Jian Peng , Xiangzhan Yang , Lianhua Wang
{"title":"Two-to-one internal resonance response of a suspended cable with time-delayed positive velocity feedback control","authors":"Yanan Li , Jian Peng , Xiangzhan Yang , Lianhua Wang","doi":"10.1016/j.cnsns.2025.109171","DOIUrl":"10.1016/j.cnsns.2025.109171","url":null,"abstract":"<div><div>Vibration control of suspended cables, especially under resonance conditions, remains a challenging problem due to the complexity of the nonlinear dynamics involved. This paper investigates the suppression of suspended cable vibration under the condition of 2:1 internal resonance using time-delay feedback control. This approach aims to enhance the stability and safety of the system. A nonlinear dynamic model of the suspended cable is established, and a control design is performed based on time-delay feedback control. Numerical simulations are conducted to analyze the effects of time delay and control gain on modal amplitudes and system stability. The results indicate that time-delay feedback control significantly suppresses resonance vibrations, and an optimal combination of time delay and control gain is found, which effectively reduces vibration amplitude while ensuring system stability. The proposed control strategy provides a feasible method for the vibration control of suspended cable.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109171"},"PeriodicalIF":3.4,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704141","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}