The European Physical Journal Plus最新文献

{"title":"Dynamics and spatiotemporal chaos suppression in predator–prey models with epidemic and combined nonlinear effects","authors":"Yan Zhang,&nbsp;Feng Lai,&nbsp;Shujing Gao,&nbsp;Shuixian Yan","doi":"10.1140/epjp/s13360-026-08313-0","DOIUrl":"10.1140/epjp/s13360-026-08313-0","url":null,"abstract":"<div><p>In this paper, we investigate the dynamic properties of deterministic and spatial predator–prey systems with endemic disease in the prey population. Both the Allee effect and fear effect are incorporated into the model. The existence and stability of equilibria are examined in the deterministic system, and a detailed analysis of potential codimension-1 and codimension-2 bifurcations is provided. Conditions for the occurrence of Turing instability in the spatially extended system are established. Moreover, a time-delayed feedback control strategy is adopted to successfully stabilize spatiotemporal chaotic dynamics. Our results indicate that an increase in the disease transmission rate significantly strengthens interspecific interactions, while the Allee effect and the fear effect contribute to the stabilization of the ecosystem. Spatial heterogeneity also plays a crucial role in suppressing extreme population fluctuations and improving the resilience and stability of the full system.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mpemba effect in parametrically driven coupled oscillators under white and colored noise","authors":"Aref Pahlevani,&nbsp;Morteza Rafiee,&nbsp;Mehdi Ansari-Rad","doi":"10.1140/epjp/s13360-026-08301-4","DOIUrl":"10.1140/epjp/s13360-026-08301-4","url":null,"abstract":"<div><p>We study the Mpemba effect in a pair of linearly coupled harmonic oscillators, one of which is parametrically driven and coupled to an independent thermal bath. Using the covariance-matrix formalism, we derive the relaxation dynamics under both Gaussian white noise and Lorentzian colored noise, including single-channel and dual-channel noise embeddings. We characterize relaxation through the Frobenius distance to the steady state and through the projection onto the slowest mode of the dynamical generator. Our results show that parametric driving provides the primary control knob for anomalous relaxation: as the drive approaches the boundary of the stable region explored in this work, the Mpemba crossing time decreases systematically. Colored noise further enhances the effect, with dual-oscillator Lorentzian noise producing a stronger reduction in the crossing time than single-oscillator noise and enlarging the parameter region where the Mpemba effect occurs. Nevertheless, the slow-mode structure of the drift matrix remains the dominant mechanism, while the influence of colored noise is secondary and mainly quantitative. We show that the Mpemba crossing time decreases as the system approaches the parametric stability boundary and that Lorentzian colored noise enlarges the region in the parametric and coupling strength plane where the Mpemba effect is observed.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Routes to chaos in a Darcy–Boussinesq model","authors":"Hamza Rouah","doi":"10.1140/epjp/s13360-026-08325-w","DOIUrl":"10.1140/epjp/s13360-026-08325-w","url":null,"abstract":"<div><p>This work examines the control of chaotic natural convection in a porous medium heated from below subjected to quasi-periodic gravitational modulation with two incommensurate frequencies. The governing Darcy–Boussinesq equations, coupled with the heat equation, are reduced via a spectral method to a four-dimensional system of ordinary differential equations. The model admits three equilibria including a motionless steady state and two convective steady states whose local stability is fulfilled. Numerical simulations performed using the fourth-order Runge–Kutta method show that the modulation frequency ratio and tilt angle significantly influence the dynamics, leading to periodic, oscillatory, and chaotic convection regimes. The transition to chaos occurs through period-doubling, intermittency, quasi-periodic, and crisis scenarios, as confirmed by bifurcation diagram. These results highlight the potential of quasi-periodic gravitational modulation as a mechanism for controlling convection in porous media.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prescription dependence of the perfect-fluid Lagrangian and conservation constraints in non-minimally coupled gravity","authors":"G. A. Carvalho,&nbsp;R. V. Lobato","doi":"10.1140/epjp/s13360-026-08342-9","DOIUrl":"10.1140/epjp/s13360-026-08342-9","url":null,"abstract":"<div><p>The matter Lagrangian of a perfect fluid is often regarded as ambiguous, representable on-shell by either the pressure <i>p</i> or the energy density <span>(varepsilon)</span>. We show that this is instead a variational prescription dependence with a physically preferred branch, and that non-minimal geometry-matter coupling promotes it to a dynamical inequivalence. In General Relativity, rest-mass conservation and the isentropic first law fix <span>(mathcal {L}=varepsilon)</span> when the densitized current <span>(J^mu =sqrt{-g},rho u^mu)</span> is held fixed under metric variation, holding the bare current <span>(delta j^mu =0)</span> fixed reproduces <span>(mathcal {L}=-p)</span> only as a formal reduced off-shell branch, it does not preserve the densitized particle-number flux under generic metric variations and is thermodynamically admissible only when <span>(-rho ,text {d}p/text {d}rho =varepsilon +p)</span>. Thus, <span>(mathcal {L}=-p)</span> is a restricted effective representation tied to a distinct off-shell prescription, not an interchangeable label. In <span>(f(R,mathcal {L}))</span> and <i>f</i>(<i>R</i>, <i>T</i>) gravity the field equations depend explicitly on <span>(mathcal {L})</span> or on <span>(Theta _{mu nu }=g^{alpha beta }delta T_{alpha beta }/delta g^{mu nu })</span>, so the two prescriptions source different gravitational dynamics. Imposing <span>(nabla _mu T^{mu nu }=0)</span> in <span>(f(R,mathcal {L}))</span> gravity gives branch-dependent constraints: a spatial condition <span>(h^mu {}_nu nabla _nu f_{mathcal {L}}=0)</span> for <span>(mathcal {L}=varepsilon)</span> and a temporal one <span>(u^nu nabla _nu f_{mathcal {L}}=0)</span> for the formal <span>(mathcal {L}=-p)</span> branch. On the restricted overlap where both are admissible (<span>(varepsilon +p=text {const})</span>), branch-independent conservation requires <span>(nabla _mu f_{mathcal {L}}=0)</span>; imposed off-shell for arbitrary independent gradients of <i>R</i> and <span>(mathcal {L})</span>, this forces <span>(f(R,mathcal {L})=F(R)+lambda mathcal {L})</span> and removes the non-minimal <i>R</i>-<span>(mathcal {L})</span> coupling. For the linear model <span>(f(R,T)=R+2lambda T)</span>, the two branches yield different effective density-scaling indices and hence distinct expansion histories <i>H</i>(<i>z</i>) for the same matter content. A consistent perfect-fluid description in non-minimally coupled gravity must therefore specify its variational prescription and thermodynamic variables.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08342-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical modeling and control of influenza A incorporating antiviral treatment and healthcare campaigns","authors":"Sharada Nandan Raw,&nbsp;Supriya Paikra","doi":"10.1140/epjp/s13360-026-08236-w","DOIUrl":"10.1140/epjp/s13360-026-08236-w","url":null,"abstract":"<div><p>In this work, we develop the transmission dynamics using a compartmental model of influenza in the context of Chhattisgarh, India. Surveillance data from December 2015–2017 are used in order to explain the cases and geographic disperse of flu infection. Through data fitting, epidemiological parameters are estimated, using the total reported case data with the help of the least squares method. We compute the basic reproduction number <span>(R_0)</span> via the next-generation matrix approach. The Routh-Hurwitz criteria are used to examine the assessment of local stability at the disease-free equilibrium (DFE). The presence of the endemic equilibrium (EE) is established both analytically as well as numerically and a sensitivity analysis is used to identify the key components contributing to transmission of illness. Additionally, optimal control strategies incorporating antiviral treatment and healthcare awareness campaigns are introduced to enhance intervention outcomes. The cost-effectiveness of these strategies is assessed using an incremental cost-effectiveness ratio (ICER) analysis. Numerical simulations help to show differences in disease burden across scenarios, examine the potential impact of targeted intervention approaches, and examine the influence of crucial epidemiological parameters on the infected population over time. Overall, this modeling framework provides a foundation for evidence-based influenza control through demographically tailored treatment strategies for Chhattisgarh to improve intervention effectiveness.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green transition of gases employed for radiation detection in nuclear and high-energy physics experiments","authors":"Marco Garbini","doi":"10.1140/epjp/s13360-026-08239-7","DOIUrl":"10.1140/epjp/s13360-026-08239-7","url":null,"abstract":"","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-stability analysis of rotatably memristive hidden chaotic sea and its application in image encryption","authors":"Xiaoying Lv,&nbsp;Qianqian Chen","doi":"10.1140/epjp/s13360-026-08298-w","DOIUrl":"10.1140/epjp/s13360-026-08298-w","url":null,"abstract":"<div><p>In this work, a three-dimensional continuous chaotic seed differential equation coupling dual memristors is proposed. Due to the paranoid boosting function of <i>sin</i>(<i>x</i>), the new differential dynamic system can coin an infinitely many coexistence attractors on <i>z</i> direction. By analyzing the stability of system, we discover that the differential system has eternal points under certain control parameter values. After passing the systematic curl test, it is regarded as a conservative dynamic model if <i>sin</i>(<i>z</i>)=0. Therefore, the system is determined can generate a hidden chaotic sea. This particular dynamic behavior is highly worthy of in-depth study. And then, after being constructed through the rotation matrix, an infinite number of coexisting rotating hidden attractive seas are formed. We construct a high-performance encryption scheme based on the chaotic signals. Experimental data demonstrate that the high security and robustness of encipherment scheme.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Final state sensitivity and fractal basin boundaries from coupled Chialvo neurons","authors":"Bennett Lamb,&nbsp;Brandon B. Le","doi":"10.1140/epjp/s13360-026-08264-6","DOIUrl":"10.1140/epjp/s13360-026-08264-6","url":null,"abstract":"<div><p>We investigate and quantify the basin geometry and extreme final state uncertainty of two identical electrically asymmetrically coupled Chialvo neurons. The system’s diverse behaviors are presented, along with the mathematical reasoning behind its chaotic and nonchaotic dynamics as determined by the structure of the coupled equations. The system is found to be multistable with two qualitatively different attractors. Although each neuron is individually nonchaotic, the chaotic basin takes up the vast majority of the coupled system’s state space, but the nonchaotic basin stretches to infinity due to chance synchronization. The boundary between the basins is found to be fractal, leading to extreme final state sensitivity. This uncertainty and its potential effect on the synchronization of biological neurons may have implications for understanding neuronal biology.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08264-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust femtosecond soliton mode-locking with accelerated buildup enabled by self-assembled tannic acid on tapered fiber","authors":"Yanqin Ren,&nbsp;Kang Li,&nbsp;Yijie Guan,&nbsp;Zhenzhou Song,&nbsp;Xingzhuo Li,&nbsp;Chen Gao,&nbsp;Zhengfan Li,&nbsp;Qingping Hu","doi":"10.1140/epjp/s13360-026-08308-x","DOIUrl":"10.1140/epjp/s13360-026-08308-x","url":null,"abstract":"<div><p>A passively mode-locked fiber laser at 1.5 <span>(upmu)</span>m is demonstrated using a tannic acid-coated tapered fiber as a saturable absorber. The conformal tannic acid coating ensures strong evanescent-field overlap, yielding low insertion loss, high environmental resilience, and excellent interfacial reliability. The extended <span>(pi)</span>-electron delocalization of tannic acid contributes to both a large transition dipole moment for strong ground-state absorption and an ultrafast electronic polarization response for rapid carrier recovery, which underlies the observed saturable absorption performance. Stable mode-locking at 86 mW pump power generates 454 fs pulses at 1563.7 nm with an 8.4 nm bandwidth, 28.01 MHz repetition rate, and 77.17 dB signal-to-noise ratio. Spatiotemporal evolutions reveal that the absorber effectively suppresses transient multi-pulse competition, enabling a direct transition to stable single-pulse mode-locking and shortening the buildup time by 0.22 ms. Loosely bound soliton molecules are also observed, underscoring the rich nonlinear dynamics. These results suggest that tannic acid is a low-cost saturable absorber with performance suitable for femtosecond pulse generation.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear dynamics and food image encryption based on a discrete memristive Hopfield neural network","authors":"Zihuan Zhao,&nbsp;Leichang Huang,&nbsp;Yinghong Cao","doi":"10.1140/epjp/s13360-026-08314-z","DOIUrl":"10.1140/epjp/s13360-026-08314-z","url":null,"abstract":"<div><p>With the continuous advancement of neuroscience research, understanding of neuronal internal structures and information transmission mechanisms continues to deepen, promoting the development of bio-inspired artificial neuron models as an important approach for exploring brain function mechanisms. In this paper, a discrete memristor with synaptic plasticity characteristics is designed and incorporated into a two-dimensional discrete Hopfield neural network to establish a discrete memristive Hopfield neural network (DMHNN). Stability analysis of equilibrium points identifies the potential unstable regions leading to complex dynamical behaviors and reveals the critical conditions for chaos generation. Further investigations demonstrate that the proposed neuron model exhibits rich nonlinear dynamical characteristics, including complex bifurcation evolution, hyperchaotic behavior, multistability, and high complexity. In terms of hardware implementation, the strange attractors generated by the model are successfully verified through digital circuit implementation, demonstrating its engineering feasibility. Finally, a food image encryption scheme is developed based on the high-complexity chaotic sequences generated by the model, enabling effective protection of various types of food images. Experimental results indicate that the proposed scheme achieves favorable encryption performance, high key sensitivity, and strong security.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}