IF 3.4 2区数学

Applied Mathematics and Computation Pub Date : 2025-08-01 DOI: 10.1016/j.amc.2025.129667

Qingfang Ye, Fengwei Li

{"title":"The minimum atom-bond sum-connectivity index of graphs with given degree sequence","authors":"Qingfang Ye, Fengwei Li","doi":"10.1016/j.amc.2025.129667","DOIUrl":"10.1016/j.amc.2025.129667","url":null,"abstract":"<div><div>The atom-bond sum-connectivity (ABS) index of a graph <math><mi>G</mi><mo>=</mo><mo>(</mo><mi>V</mi><mo>,</mo><mi>E</mi><mo>)</mo></math> is described as the formula <math><mi>A</mi><mi>B</mi><mi>S</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>=</mo><msub><mrow><mo>∑</mo></mrow><mrow><mi>ξ</mi><mi>ζ</mi><mo>∈</mo><mi>E</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow></msub><msqrt><mrow><mfrac><mrow><mi>d</mi><mo>(</mo><mi>ξ</mi><mo>)</mo><mo>+</mo><mi>d</mi><mo>(</mo><mi>ζ</mi><mo>)</mo><mo>−</mo><mn>2</mn></mrow><mrow><mi>d</mi><mo>(</mo><mi>ξ</mi><mo>)</mo><mo>+</mo><mi>d</mi><mo>(</mo><mi>ζ</mi><mo>)</mo></mrow></mfrac></mrow></msqrt></math>, where <math><mi>d</mi><mo>(</mo><mi>ξ</mi><mo>)</mo></math> represents the degree of vertex <math><mi>ξ</mi><mo>∈</mo><mi>V</mi></math>. It is possible to forecast the heat of production of octane and heptane with accuracy by using the ABS index. This paper explores the structural properties of connected graphs with a particular degree sequence and the minimum ABS index. These findings are also applied to the characterization of extremal graphs having minimal ABS index among two types of graphs which are bicyclic or unicyclic with a specific degree sequence.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"509 ","pages":"Article 129667"},"PeriodicalIF":3.4,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749814","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

Manin triples on multiplicative Courant algebroids 乘法Courant代数上的Manin三元组

IF 0.7 4区数学

Differential Geometry and its Applications Pub Date : 2025-08-01 DOI: 10.1016/j.difgeo.2025.102273

Ana Carolina Mançur

引用次数: 0

Debiased calibration estimation using generalized entropy in survey sampling 基于广义熵的调查抽样去偏校正估计

IF 3.7 1区数学

Journal of the American Statistical Association Pub Date : 2025-08-01 DOI: 10.1080/01621459.2025.2537452

Yonghyun Kwon, Jae Kwang Kim, Yumou Qiu

引用次数: 0

Multi-parameter estimation in critical quantum metrology 临界量子计量中的多参数估计

IF 5.6 1区数学

Chaos Solitons & Fractals Pub Date : 2025-08-01 DOI: 10.1016/j.chaos.2025.116913

Giovanni Di Fresco , Bernardo Spagnolo , Davide Valenti , Angelo Carollo

引用次数: 0

Distinguishing dynamical regimes in a semiconductor laser with optical feedback by using event-detection methods. 用事件检测方法区分具有光反馈的半导体激光器的动态状态。

IF 3.2 2区数学

Chaos Pub Date : 2025-08-01 DOI: 10.1063/5.0273447

María Duque-Gijón, Cristina Masoller, Jordi Tiana-Alsina

{"title":"Distinguishing dynamical regimes in a semiconductor laser with optical feedback by using event-detection methods.","authors":"María Duque-Gijón, Cristina Masoller, Jordi Tiana-Alsina","doi":"10.1063/5.0273447","DOIUrl":"https://doi.org/10.1063/5.0273447","url":null,"abstract":"In semiconductor lasers, optical feedback generates different types of oscillations in the time trace of the emitted intensity. Depending on the laser and feedback parameters, the emission regimes can be of three main types: stable emission, Low Frequency Fluctuations (LFFs), and Coherence Collapse (CC). In the stable regime, the intensity signal shows noisy fluctuations, while in the LFF regime, these fluctuations are suddenly interrupted by large drops, during which the laser almost turns off. These reset-type events are separated by time intervals of stable emission, where the intensity displays only small fluctuations. In the CC regime, the intensity signal shows highly irregular fluctuations. We analyze experimental intensity time traces, and, by combining three event-detection methods that detect different numbers of events, and using a clustering algorithm, we show that time traces can be qualitatively distinguished within these regimes. We also find that the event-detection methods capture the gradual or abrupt nature of the transitions between the different regimes. Importantly, these methods offer potential to advance the long-standing challenge of distinguishing high-dimensional chaos from noise, since we can differentiate time traces recorded below the laser threshold, where the dynamics is dominated by noise, and well above threshold, where the dynamics is dominated by nonlinearity and feedback. Our results are also relevant to the scientific community working with stochastic point process data (cardiac beats, neuronal discharges, seismic data, extreme precipitation, price spikes, etc.), because we show that event-detection methods that detect different types of events can provide complementary information and can be useful for differentiating or discovering new features of the data.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764639","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

Emergence of a ratchet motor by spontaneous symmetry breaking. 自发对称性破缺产生棘轮马达。

IF 3.2 2区数学

Chaos Pub Date : 2025-08-01 DOI: 10.1063/5.0271467

Miku Hatatani, Junpei Oguni, Daigo Yamamoto, Akihisa Shioi

{"title":"Emergence of a ratchet motor by spontaneous symmetry breaking.","authors":"Miku Hatatani, Junpei Oguni, Daigo Yamamoto, Akihisa Shioi","doi":"10.1063/5.0271467","DOIUrl":"https://doi.org/10.1063/5.0271467","url":null,"abstract":"A circular disk without any asymmetry exhibits a one-way spin on a vibrating granular layer. Vertical agitation generates a random motion of particles by mutual collision. A circular disk, placed on the layer with its center fixed, is moved by collision with the particles. After the vibration began, the circular disk exhibits a one-way spin in a stochastic manner. Before the start of the one-way spin, the particles, which were homogeneously distributed under the disk at the initial state, spontaneously gather on one side, forming an asymmetric distribution of particles. This asymmetric distribution causes the disk-inclination. Simultaneously, the agitated particles cannot enter the lower part of the inclined disk. Resultantly, the disk-inclination and the asymmetric distribution of particles maintain the situation with stable manner. Then, the inclined disk rotates with the precession movement around this inclined axis. The disk-spin is synchronized with the rotation of the disk-inclination. This phenomenon can be reproduced by a simple mathematical model referring to the precession movement of a spinning top. Though the present system may be regarded as a type of ratchet motor, any asymmetries are not equipped in the initial setup. To the best of our knowledge, this is the first ratchet motor to produce an asymmetric structure in a self-organizing manner.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764642","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

Quantifying the likelihood of learning collusive strategy equilibria. 量化学习串通策略均衡的可能性。

IF 3.2 2区数学

Chaos Pub Date : 2025-08-01 DOI: 10.1063/5.0281443

Janusz M Meylahn

引用次数: 0

Dynamical analysis and solutions of coupled 4D fractional differential systems with applications to predictability limit quantification in ocean-atmosphere models. 耦合四维分数微分系统的动力学分析和解及其在海洋-大气模式可预测性极限量化中的应用。

IF 3.2 2区数学

Chaos Pub Date : 2025-08-01 DOI: 10.1063/5.0283492

Xiaoyu Chen, Hongtao Fan, Yajing Li

{"title":"Dynamical analysis and solutions of coupled 4D fractional differential systems with applications to predictability limit quantification in ocean-atmosphere models.","authors":"Xiaoyu Chen, Hongtao Fan, Yajing Li","doi":"10.1063/5.0283492","DOIUrl":"https://doi.org/10.1063/5.0283492","url":null,"abstract":"For coupled two-dimensional fractional differential systems, a new two-step fractional-order Runge-Kutta method is proposed in this paper, which can reach a convergence order of 2α, with α being the fractional-order number. Further, we extend the two-step fractional-order Runge-Kutta algorithm to any coupled n-dimensional fractional differential system while maintaining convergence and consistency. To demonstrate the validity of the proposed method, numerical experiments are given for a four-dimensional fractional Lorenz system, and the dynamics of the four-dimensional fractional Lorenz system is analyzed using Lyapunov characteristic exponents, bifurcation diagrams, chaos diagrams, and C0 complexity. The results demonstrate that the system exhibits a diverse dynamical behavior and a broader range of fractional orders [0.43, 1] is accessible to the periodic orbit at the same parameter, compared to previous findings [He et al., Math. Methods Appl. Sci. 39, 2965-2973 (2016)]. Finally, we use global attractor radius and attractor radius to investigate the predictability of the coupled fractional-order ocean-atmosphere system [Li et al., Clim. Dyn. 51, 2359-2374 (2018)]. The results show that both global attractor radius and attractor radius decrease with decreasing fractional order, and the smaller the initial perturbation, the longer it takes to reach the attractor radius, but the attractor radius to the global attractor radius is not significantly correlated with the initial perturbation. These findings suggest that the predictability of the coupled fractional ocean-atmosphere system is limited by the presence of long-range memory effects captured in the fractional-order differential equations. By offering quantitative assessments of predictability, these approaches enhance our understanding of the intricate dynamics within such systems and can support informed decision-making in addressing and mitigating the effects of climate change on the global atmosphere and oceans.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764641","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

Dynamic analysis of a generalized attention deficit disorder model with Soboleva activation functions. 具有Soboleva激活函数的广义注意缺陷障碍模型的动态分析。

IF 3.2 2区数学

Chaos Pub Date : 2025-08-01 DOI: 10.1063/5.0280557

L Moysis, M Lawnik, K F Kollias, M S Baptista, S Goudos, G Fragulis

引用次数: 0

Recurrence condensation during critical transitions in complex systems. 复杂系统临界跃迁过程中的重复凝聚。

IF 3.2 2区数学

Chaos Pub Date : 2025-08-01 DOI: 10.1063/5.0267157

Manaswini Jella, Induja Pavithran, Vishnu R Unni, Norbert Marwan, Jürgen Kurths, R I Sujith

{"title":"Recurrence condensation during critical transitions in complex systems.","authors":"Manaswini Jella, Induja Pavithran, Vishnu R Unni, Norbert Marwan, Jürgen Kurths, R I Sujith","doi":"10.1063/5.0267157","DOIUrl":"https://doi.org/10.1063/5.0267157","url":null,"abstract":"Critical transitions in complex systems pose challenges for the healthy functioning of natural and engineered systems, sometimes with catastrophic outcomes. These critical points, where small changes cause large regime shifts, are difficult to detect-especially in noisy, high-dimensional settings. We investigate such a transition from chaotic to periodic oscillations via intermittency in a turbulent fluid mechanical system by using recurrence analysis. Recurrence plots (RPs) constructed from the time series of a state variable reveal a distinct progression from disordered, short broken diagonal lines to patches of ordered short diagonal lines and, ultimately, to a pattern of long continuous diagonal lines. This evolution in the recurrence patterns captures a transition from dynamics involving multiple time scales to a dominant single time scale; we term this phenomenon \"recurrence condensation.\" We quantify recurrence condensation using recurrence quantification measures, such as the recurrence time, determinism, entropy, laminarity, and trapping time, all of which show collapse to a single dominant time scale. Furthermore, these recurrence measures exhibit power-law scaling with the deviation of the control parameter from the critical point. Optimizing for the best power law reveals the critical value of the parameter. We apply this method to the synthetic data from a basic noisy Hopf bifurcation model and confirm that the detected critical point coincides with the bifurcation point. Our findings offer insights into identifying the critical points in noisy systems with gradual transitions, where the transition point is not well defined.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764644","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

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