Chaos最新文献

{"title":"Erratum: \"Spectral-gradient iterative edge attack for synchronization suppression in complex networks\" [Chaos 36, 023137 (2026)].","authors":"Kaiming Luo","doi":"10.1063/5.0363959","DOIUrl":"https://doi.org/10.1063/5.0363959","url":null,"abstract":"","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318497","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":"Geometric transition of latent dynamics in intermittent chaos: SVD-based effective dimension for detection and proactive control.","authors":"Takashi Hikihara, Tetsushi Saburi","doi":"10.1063/5.0337083","DOIUrl":"https://doi.org/10.1063/5.0337083","url":null,"abstract":"<p><p>This paper investigates the geometric detection of latent dynamic transitions (where the latent space is defined as a finite-dimensional state space reconstructed via a delay-embedding Hankel matrix) in mutually coupled phase-locked loops exhibiting on-off intermittent chaos. We propose a data-driven approach to identify the transition of the effective dimension in latent dynamics as a precursor to physical bursting events. By applying Singular Value Decomposition to a Hankel matrix constructed from high-resolution oversampled data, we extract the effective dimension that reflects the dynamical shift of intrinsic variables-from a synchronized two-dimensional manifold to a higher-dimensional chaotic state-prior to the actual burst. This geometric indicator enables a proactive, event-driven intervention using Pyragas-type delayed feedback control, which is activated only when the detected dimension exceeds a critical threshold. Simulation results demonstrate that this geometric precursor effectively compensates for control latencies and substantially reduces accumulated control energy compared to conventional continuous feedback. The findings establish a methodological strategy for stabilizing infinite-dimensional delayed systems by exploiting early warning signals embedded in dimensional transitions of latent dynamics.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318499","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":"Environmental feedback sign shapes cooperation and collapse in eco-evolutionary networks.","authors":"Bingkun Zhao, Li Xie","doi":"10.1063/5.0358827","DOIUrl":"https://doi.org/10.1063/5.0358827","url":null,"abstract":"<p><p>Cooperation in a system with a shared renewable resource is shaped by a feedback loop: individual actions alter the resource, which in turn changes the payoff to cooperation. We study this loop in a spatial evolutionary game with a signed feedback strength λ. For an isolated interior fixed point on the differentiable, unclipped branch of the mutation-free mean-field model, negative feedback (λ < 0) makes the fixed point locally attracting, whereas positive feedback (λ > 0) makes it a saddle. This local classification provides a reference for the spatial dynamics. At the sampled negative-feedback operating points, demographic noise produces quasi-cycles: their amplitude scales as N-1/2, the rescaled spectra collapse with system size, and resource fluctuations lag cooperation by approximately 1 rad. Under positive feedback, runs initialized in the prosperous and desert states remain strongly separated over the observation window, and recovery slows near the loss of prosperity. Resource diffusion can reverse the motion of a depleted patch from retreat to invasion, with the two regimes separated by a zero-velocity boundary. In multiplex systems, weak mass-conserving exchange can rescue a damaged layer, whereas stronger exchange can spread the deficit and promote joint collapse. The same qualitative contrast persists on the tested square lattices, small-world networks, and scale-free networks under cumulative payoffs. The results show how the sign of a strategy-resource feedback organizes fluctuations, spatial invasion, and interdependent failure.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149332729","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":"Structural analysis of opinion columns using ordinal patterns and information-theoretic measures.","authors":"Cynthia Z Zhou-Lin, José L Herrera-Diestra, Luciano Stucchi","doi":"10.1063/5.0354862","DOIUrl":"https://doi.org/10.1063/5.0354862","url":null,"abstract":"<p><p>Source attribution in journalistic text is typically approached through semantic representations, such as term weighting or neural embeddings. These approaches capture topical content, but usually overlook how a text is organized as a sequence. Here, we show whether content-independent ordinal descriptors of such sequences can identify the source that published an opinion column. We converted 1262 columns from 14 Peruvian online newspapers into numerical sequences using two encodings, word length and lexical frequency, and an exploratory part-of-speech (POS) encoding. From non-overlapping blocks with D = 3, we calculated pattern and transition probabilities, permutation entropy, disequilibrium, and statistical complexity. The apparent dominance of pattern 012 is mostly a tie-breaking artifact whose size depends on stopword removal. Under random tie-breaking, its share falls from 23.7% and 48.1% to about 17%, and K-means clusters barely match the newspapers (ARI ≤0.05). Classified against the true sources, the lexical encodings reach accuracies of 0.18-0.29, above the 0.08 majority baseline but below a function-word baseline (0.43), and neither shuffling tokens within each document nor retaining stopwords changes them. Their signal lies in the marginal distribution of the encoded values and in column length, not in word order. Only POS-tag order outperformed all 20 shuffled surrogates with both classifiers, although the effect is small. Therefore, tie handling, surrogate tests, and targets that do not come from the features themselves are needed before ordinal descriptors of text are read as stylistic fingerprints.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149332730","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":"Adaptive dynamics of eco-evolutionary repeated games: Effect of reward and punishment.","authors":"Prosanta Mandal, Suman Chakraborty, Vaibhav Madhok, Sagar Chakraborty","doi":"10.1063/5.0349579","DOIUrl":"https://doi.org/10.1063/5.0349579","url":null,"abstract":"<p><p>Long-term evolutionary processes can strongly influence common-pool resource conservation by generating new traits or behaviors that modify the feedback between population strategies and the resource state. Here, we develop an eco-evolutionary framework in which individuals repeatedly interact with the same opponent and follow direct reciprocity through reactive strategies. The strategic dynamics are coupled to a renewable common resource and analyzed using adaptive dynamics. After our exhaustive non-linear dynamical analysis of 2 × 2 strategic games, we focus on comparative and combined usefulness of institutional incentives in the form of rewards and punishments in preventing the tragedy of the commons even when defection dominates in the replete resource state. We also report possibility of robust stable oscillations-emerging via Hopf bifurcation-in resource state and population strategies.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318493","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":"Data-driven reduction of action-potential models using SINDy.","authors":"M A S de Carvalho, R W Dos Santos, B M Rocha","doi":"10.1063/5.0336856","DOIUrl":"https://doi.org/10.1063/5.0336856","url":null,"abstract":"<p><p>Mathematical models of excitable cells, such as neurons and cardiac myocytes, are fundamental tools for understanding electrical activity and action-potential generation. However, biophysically detailed models often involve numerous state variables, making their simulation computationally demanding in the context of tissue or whole-organ level. In this work, we explore a data-driven alternative for model discovery and reduction based on the Sparse Identification of Nonlinear Dynamics (SINDy) framework. Using the classical Hodgkin-Huxley model as the reference system, we introduce an ionic current-based approach in which reduced variables are constructed directly from membrane current measurements and fitted using physically structured sparse libraries, enabling compact surrogate models of the ionic dynamics. The method can reproduce the essential dynamics of action-potential generation with compact representations. For the Hodgkin-Huxley model, we further combine principal component analysis with SINDy to reduce the dimensionality of the system equations prior to identification, yielding low-dimensional models that accurately reproduce excitable dynamics. These results highlight the potential of a data-driven approach to derive models of excitable membranes, paving the way for the reduction of electrophysiological models based on ionic current data and for large-scale or real-time neuronal and cardiac simulations.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318494","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":"Subharmonic bifurcation and multi-solution coexistence mechanism in fractional-order piecewise smooth impact systems under different resonance conditions.","authors":"Jiaquan Xie, Yanan Li, Wei Shi, Jiale Zhang, Xiaolin Zhu, Haijun Wang","doi":"10.1063/5.0341195","DOIUrl":"https://doi.org/10.1063/5.0341195","url":null,"abstract":"<p><p>This paper systematically investigates the evolutionary law of the existence of subharmonic solutions for a two-degree-of-freedom piecewise-smooth vibro-impact vibration system across four resonance types. Via Hamiltonian normalization, the original system is transformed into a Hamiltonian form, and fractional-order memory damping and nonlinear stiffness are integrally incorporated into the analytical construction of the Melnikov function, which extends the applicability of the existing Melnikov theory to multi-factor coupled systems. Combined with the subharmonic solution bifurcation theorem, the criteria for the existence of solutions are obtained, and a unified analytical framework covering subharmonic resonance, double subharmonic resonance, super-harmonic resonance, and double super-harmonic resonance is established. Theoretical determination of the number of subharmonic solutions, the coexistence of multiple solutions, and the deterministic evolutionary characteristics of the solutions are realized through verification of the zero distribution of the Melnikov function and the Jacobian determinant. We quantify how excitation amplitude, fractional order, nonlinear stiffness, and linear damping regulate solution coexistence by altering Melnikov zeros. The results show that the system can exhibit multi-solution coexistence characteristics, corresponding to multiple coexisting periodic orbits. Double subharmonic resonance presents a nested trajectory structure, whose time-series responses satisfy fixed time-series frequency ratios. Under super-harmonic resonance and double super-harmonic resonance, the system violates the Jacobian non-vanishing criterion, admitting no nearby subharmonic solutions. In this paper, the variation law of subharmonic solutions under the regulation of excitation amplitude is verified by the visualization of phase trajectories and time-series responses, which provides a theoretical basis for the dynamic design and vibration control of piecewise-smooth mechanical systems.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149332666","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":"Recovering nonlinear dynamics from first-passage events: A Markov process inversion approach with application to gene expression variability.","authors":"Xuyan Xiang, Beilin Xiang, Jieming Zhou","doi":"10.1063/5.0350128","DOIUrl":"https://doi.org/10.1063/5.0350128","url":null,"abstract":"<p><p>Stochastic nonlinear systems, from gene circuits to financial markets, are ubiquitous. A key challenge is inferring their governing parameters from sparse event times rather than continuous trajectories. We introduce a Markov process inversion approach (MPIA) that recovers drift and diffusion coefficients of nonlinear diffusions solely from first-passage times to a fixed boundary. Using arithmetic and geometric Brownian motions-representing constant-coefficient and state-dependent (log-linear) diffusions, respectively-the latter a paradigmatic model of multiplicative noise capturing state-dependent fluctuations-we develop a two-step procedure: fitting the inverse Gaussian distribution to hitting times, then analytically recovering generator parameters. We provide a comprehensive analysis of distribution fitting strategies, including maximum likelihood, Bayesian, and robust methods, and establish their relative merits. Asymptotic normality and consistency are proven, and the method is validated through high-precision simulations involving both direct sampling and full-path simulation. Applied to a synthetic gene circuit, MPIA disentangles effective growth rate from noise strength using only threshold-crossing times-readily accessible in high-throughput microfluidic experiments but invisible to trajectory-based methods. This event-based framework directly addresses the data constraints of modern single-cell technologies, where photobleaching and storage limitations make continuous fluorescence tracking impractical for large populations. Practical guidelines for handling censored data, drift direction verification, and model diagnostics are provided. This work lays a foundational blueprint for inversion strategies tailored to diffusions with analytically tractable first-passage-time distributions-specifically, constant-coefficient, log-linear, and the broader class of Lamperti-reducible diffusions. Extensions to non-reducible models, such as Ornstein-Uhlenbeck, Cox-Ingersoll-Ross, and logistic diffusions, via spectral and moment-based techniques, are discussed as future directions.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318500","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":"Shot noise generated by subpopulations of neural networks.","authors":"S Yu Kirillov, O A Goryunov, J Zhu, V V Klinshov","doi":"10.1063/5.0344204","DOIUrl":"https://doi.org/10.1063/5.0344204","url":null,"abstract":"<p><p>While the so-called next-generation neural mass models provide exact descriptions of densely coupled neural populations in the thermodynamic limit, finite-size effects introduce stochastic fluctuations whose power spectrum we derived in our previous work. However, coupling between different populations in the brain is typically sparse, meaning that only a subset of neurons from one population actually projects connections to another. This necessitates the study of shot noise generated by subpopulations within densely coupled neural populations. In the present work, we perform such an analysis and show that the shot noise of subpopulations differs from that of the whole population in both intensity and spectral properties, depending non-trivially on subpopulation size. Generalizing the previously introduced nesting method, we derive an analytical expression for the power spectrum of subpopulation shot noise, which shows excellent agreement with direct numerical simulations. Importantly, our approach accounts for realistic, non-Lorentzian distributions of local neuron parameters using a previously developed reduction technique. Thus, our results constitute an important step toward a new class of stochastic mean-field models suited for hierarchical neural networks with dense local connectivity and sparse inter-population connectivity.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318502","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":"Sequential cascades on random hypergraphs.","authors":"Yiqi Zhang, Fanyuan Meng","doi":"10.1063/5.0355277","DOIUrl":"https://doi.org/10.1063/5.0355277","url":null,"abstract":"<p><p>Sequential decisions within a group can correlate individual adoption outcomes, but this microscopic dependence is usually replaced by an imposed group-level response. We study a one-shot cascade on sparse random hypergraphs in which the first target in a newly triggered hyperedge adopts with probability p, whereas each later target adopts with probability p + Δ after a success and p - δ after a failure. For this stated process, we derive the exact target marginal qm, the complete correlated group-offspring probability-generating function Fm(z), and the early branching factor B. The classical Galton-Watson criterion then places the infinitesimal-seed onset at B=1, while its extinction fixed point depends on the complete offspring law. The new ingredients are the exact transfer-matrix offspring law for outcome memory and a matched-independent hypergraph control with the same qm and onset. For the original-cardinality null, directed-incidence percolation gives Rnull = ρnullSnull; the forward-survival and backward-reachability maps coincide for pairwise groups but generally differ for larger groups. Monte Carlo tests across group-size and degree laws support the threshold and survival predictions. A collision-aware control, which rematches the null to the number of targets actually remaining at first processing, reduces but does not remove the observed final-size gap at the tested parameters. System-size and cutoff sweeps likewise show that the 5% finite-network indicator is a proxy rather than the branching-survival probability. All claims are conditional on one-shot triggering, a vanishing seed density, and locally tree-like topology.</p>","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"36 11","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149318501","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}