Physica A: Statistical Mechanics and its Applications最新文献

{"title":"Variational supersymmetric approach and Gram–Schmidt process for evaluating Fokker–Planck probabilities","authors":"João Vitor Santos Perles , Hugo de Oliveira Batael , Elso Drigo Filho","doi":"10.1016/j.physa.2025.130952","DOIUrl":"10.1016/j.physa.2025.130952","url":null,"abstract":"<div><div>In this work, an alternative method for solving eigenvalue equations is investigated, with a specific application to the Schrödinger-type Fokker–Planck equation. This method is based on combined eigenfunctions through the Gram–Schmidt orthogonalization process, coupled with the well-formalized factorization technique in supersymmetric quantum mechanics. Eigenvalues are obtained via the variational method, using numerical computation. The aim is to obtain solutions for two polynomial potentials of the form <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>1</mn></mrow></msub><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>6</mn></mrow></msup></mrow><mrow><mn>6</mn></mrow></mfrac><mo>−</mo><mfrac><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>4</mn></mrow></msup></mrow><mrow><mn>4</mn></mrow></mfrac></mrow></math></span> and <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>2</mn></mrow></msub><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>4</mn></mrow></msup></mrow><mrow><mn>4</mn></mrow></mfrac><mo>−</mo><mfrac><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow><mrow><mn>5</mn></mrow></mfrac><mo>−</mo><mfrac><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></math></span>, in order to obtain the probability distributions at different times <span><math><mi>t</mi></math></span> and initial conditions represented by <span><math><msub><mrow><mi>x</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>. The results for the symmetric potential <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>1</mn></mrow></msub><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span> are compared with values found in the literature. For the asymmetric potential <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>2</mn></mrow></msub><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span>, the solution is compared only with numerical results, also demonstrating a low margin of error. In both cases, the proposed technique generates probability distributions that respect the typical behavior of the Fokker–Planck equation, with percentage errors below 0.5% compared to reference methods.</div><div>The study demonstrates that the approach based on Gram–Schmidt orthogonalization and the variational method is an effective and alternative tool for solving the Fokker–Planck equation in systems described by polynomial potentials, reliably reproducing results for both ground and excited states.</div><div>As a possible application, the method is employed to investigate the folding dynamics of the protein <span><math><mrow><mi>C</mi><mi>I</mi><mn>2</mn></mrow></math></span>, treating folding as a diffusive process governed by the Fokker–Planck equation. A bistable polynomial potential of the form <span><math><mrow><mi>V</mi><mrow><mo>(</mo>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130952"},"PeriodicalIF":3.1,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106672","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":"The von Neumann entropy and quantum statistical features of a degenerate parametric amplifier system","authors":"Yang Yang ,&nbsp;Li-Li Xu ,&nbsp;Zong-Zhen Gao ,&nbsp;Xiang-Guo Meng","doi":"10.1016/j.physa.2025.130954","DOIUrl":"10.1016/j.physa.2025.130954","url":null,"abstract":"<div><div>Using the theory of partition function and the operator ordering method, we obtain the normalized density operator that describes the degenerate parametric amplifier system, and present its theoretical generation scheme. Also, we analytically and numerically investigate the quantum statistical properties and von Neumann entropy. It is found that the frequency of signal light can weaken the nonclassicality and the von Neumann entropy of the new state, however the interaction between light and medium can enhance them. This work provides a theoretical basis for the measurement and application of quantum entropy in quantum information.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130954"},"PeriodicalIF":3.1,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027316","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":"Critical dynamics of random surfaces: Time evolution of area and genus","authors":"Christof Schmidhuber","doi":"10.1016/j.physa.2025.130959","DOIUrl":"10.1016/j.physa.2025.130959","url":null,"abstract":"<div><div>Conformal field theories with central charge <span><math><mrow><mi>c</mi><mo>≤</mo><mn>1</mn></mrow></math></span> on random surfaces have been extensively studied in the past. Here, this discussion is extended from their equilibrium distribution to their critical dynamics. This is motivated by the conjecture that these models describe the time evolution of certain social networks that are self-driven to a critical point. This paper focuses on the dynamics of the overall area and the genus of the surface. The time evolution of the area is shown to follow a Cox–Ingersoll–Ross process. Planar surfaces shrink, while higher genus surfaces grow to a size of order of the inverse cosmological constant. The time evolution of the genus is argued to lead to two different phases, dominated by (i) planar surfaces, and (ii) “foamy” surfaces, whose genus diverges. In phase (i), which exhibits critical phenomena, time variations of the order parameter are approximately t-distributed with 4 or more degrees of freedom.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130959"},"PeriodicalIF":3.1,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047017","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":"Phase diagram of the decorated Ising model on the Kagome lattice with ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor interactions","authors":"Vadim A. Mutailamov,&nbsp;Akai K. Murtazaev","doi":"10.1016/j.physa.2025.130953","DOIUrl":"10.1016/j.physa.2025.130953","url":null,"abstract":"<div><div>Using computational physics methods, we investigate the static critical behavior of the decorated Ising model on a Kagome lattice. The model incorporates exchange interactions between nearest-neighbor nodal spins, next-nearest-neighbor nodal spins, as well as interactions between nodal and nearest decorated spins. The analysis is performed for various values of the exchange coupling between nodal and decorated spins. We compute critical temperatures, determine equilibrium spin configurations at finite temperatures, characterize the nature of phase transitions, and construct the corresponding phase diagram. Our results demonstrate that the inclusion of decorated spins induces the emergence of novel phases and additional phase transition lines.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130953"},"PeriodicalIF":3.1,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047024","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":"Collective dynamics in a Vicsek model with Metropolis-based interactions","authors":"Dorilson S. Cambui","doi":"10.1016/j.physa.2025.130958","DOIUrl":"10.1016/j.physa.2025.130958","url":null,"abstract":"<div><div>We investigate the collective dynamics of self-propelled particles using a variant of the Vicsek model in which the local alignment rule is replaced by a Metropolis-based interaction mechanism. In this formulation, interactions depend on the angular difference between particle velocities, interpreted as an energy-like quantity that determines the acceptance probability via a Metropolis criterion. Unlike the classical Vicsek model, which restricts interactions to a radius of interaction, our approach allows particles to interact independently of distance, based solely on directional alignment. We observe that the Metropolis rule gives rise to long-range correlations that persist even at high densities. In order to investigate the phase transition, we compute the order parameter, the Binder cumulant, and the susceptibility for both models. We find that the Metropolis rule shows stronger finite-size effects and sharper susceptibility peaks, suggesting a more abrupt transition, while the Vicsek model exhibits smoother behavior consistent with a continuous transition.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130958"},"PeriodicalIF":3.1,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027317","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":"Microscopic origins of conformable dynamics: From disorder to deformation","authors":"José Weberszpil","doi":"10.1016/j.physa.2025.130945","DOIUrl":"10.1016/j.physa.2025.130945","url":null,"abstract":"<div><div>Conformable derivatives provide a mathematically tractable approach to modeling anomalous relaxation and scaling in complex systems, yet their physical origin remains poorly understood. We address this gap by deriving conformable relaxation dynamics from first principles. Our approach is based on a spatially-resolved Ginzburg–Landau model incorporating quenched disorder and temperature-dependent kinetic coefficients. Applying statistical averaging and transport-theoretic arguments, we demonstrate that spatial heterogeneity and energy barrier distributions generate power-law memory kernels of the form <span><math><mrow><mi>K</mi><mrow><mo>(</mo><mi>τ</mi><mo>)</mo></mrow><mo>∼</mo><msup><mrow><mi>τ</mi></mrow><mrow><mi>μ</mi><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>. In the adiabatic limit, these memory effects reduce to a local conformable evolution law <span><math><mrow><msup><mrow><mi>T</mi></mrow><mrow><mn>1</mn><mo>−</mo><mi>μ</mi></mrow></msup><mspace></mspace><mi>d</mi><mi>ψ</mi><mo>/</mo><mi>d</mi><mi>T</mi></mrow></math></span>. We show that the deformation parameter <span><math><mi>μ</mi></math></span> is directly linked to measurable quantities such as transport coefficients, susceptibility, energy barrier distributions, and the underlying disorder exponent. Furthermore, <span><math><mi>μ</mi></math></span> is related to Tsallis nonextensive entropy via the relation <span><math><mrow><mi>μ</mi><mo>=</mo><mn>1</mn><mo>/</mo><mrow><mo>(</mo><mi>q</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mrow></math></span>. These results establish a microscopic foundation for conformable dynamics in disordered media, provide a physical interpretation of the deformation parameter, ensure thermodynamic consistency with entropy production, and yield experimentally testable predictions. Observable consequences include specific relaxation spectra and susceptibility decay patterns. Overall, the framework unifies memory effects, nonextensive thermodynamics, and critical phenomena within a coherent and physically grounded description.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130945"},"PeriodicalIF":3.1,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106666","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":"Modeling and simulation of crowd dynamics in low-speed water flow environment","authors":"Xinyun Lan ,&nbsp;Kezhao Bai ,&nbsp;Bing Qiu ,&nbsp;Hua Kuang ,&nbsp;Xingli Li","doi":"10.1016/j.physa.2025.130936","DOIUrl":"10.1016/j.physa.2025.130936","url":null,"abstract":"<div><div>In urban waterlogging scenario, the complexity of crowd evacuation escalates exponentially due to the interference of water flow. Beyond physical obstacles, the hydrodynamic environment exerts profound psychological impacts on evacuees, often triggering abnormal behaviors such as panic and irrational herding. In this paper, an extended social force model is proposed to simulate crowd evacuation in low-speed water flow environments. Treating the water flow as a uniform flow, the model integrates multi-faceted factors, including pedestrian panic level, herd mentality, and the force exerted by the flowing water. The effects of the magnitude and direction of the water flow and individual mass on pedestrian movement stability and evacuation efficiency are explored. Macro self-organization phenomena, such as following and layering, are observed and the corresponding dynamic mechanism is analyzed. Results show that evacuation efficiency depends on water depth and the magnitude and direction of the water flow. Notably, pedestrian movement stability exhibits a positive correlation with individual mass, indicating that heavier individuals maintain better balance in water currents. These findings not only enrich the theoretical framework of hydrodynamic evacuation modeling but also provide practical guidelines for optimizing evacuation strategies in flood-prone urban areas, thereby enhancing the effectiveness of disaster prevention and mitigation efforts.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130936"},"PeriodicalIF":3.1,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020374","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":"Dissecting multifractal detrended cross-correlation analysis","authors":"Borko Stosic,&nbsp;Tatijana Stosic","doi":"10.1016/j.physa.2025.130971","DOIUrl":"10.1016/j.physa.2025.130971","url":null,"abstract":"<div><div>In this work we address the question of the Multifractal detrended cross-correlation analysis method that has been subject to some controversies since its inception almost two decades ago. To this end we propose several new options to deal with negative cross-covariance among two time series, that may serve to construct a more robust view of the multifractal spectrum among them. We compare these novel options with the proposals already existing in the literature, and we provide fast code in C, with wrapper code for R and Python, for both new and the already existing proposals. We test different algorithms on synthetic series with an exact analytical solution, uncorrelated white noise series, and on daily price series of ethanol and sugar in Brazil from 2010 to 2023.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130971"},"PeriodicalIF":3.1,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005008","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":"Modeling of car-following behavior at signalized intersection considering vehicle-vehicle and vehicle-road interactions","authors":"Yi Wang ,&nbsp;Chenjing Zhou ,&nbsp;Yanjie Zeng ,&nbsp;Yacong Gao ,&nbsp;Jian Rong ,&nbsp;Yang Xiao","doi":"10.1016/j.physa.2025.130970","DOIUrl":"10.1016/j.physa.2025.130970","url":null,"abstract":"<div><div>To analyze the effects of vehicle-vehicle and vehicle-road interactions on traffic flow at signalized intersections, this study proposes an improved car-following model based on the Full Velocity Difference (FVD) model, which considers the impact of lane width and the percentage of heavy vehicles on car-following behavior. The longitudinal space headway in the base FVD model was transformed into a comprehensive space headway with lateral and longitudinal weighted spacing to account for the vehicle-road interaction effect. The model was also segmented into four scenarios (car-car, car-bus, bus-car, and bus-bus) to account for the vehicle-vehicle interaction effect. The performance of the proposed model was validated using measured trajectory data, showing improvements in the average Root Mean Square Error (RMSE) by up to 31 % and Relative Entropy (RE) by up to 63 % compared with the base FVD model. Similarly, compared to the OV-Rong model, RMSE improved by an average of 84 % and RE improved by an average of 63 %; compared to the FVD-Liu model, RMSE improved by an average of 30 % and RE improved by an average of 52 %. Numerical simulations across 24 scenarios with different lane widths and varying percentages of heavy vehicles validated the precision of the model in capturing traffic flow characteristics. The results suggest that the improved model can accurately analyze macroscopic capacity changes based on microscopic car-following behavior under different traffic compositions and lane widths.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130970"},"PeriodicalIF":3.1,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047022","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":"Spatiotemporal analysis of traffic oscillation propagation at consecutive merging bottlenecks using trajectory data","authors":"Qiucheng Chen ,&nbsp;Wenbin Xiao ,&nbsp;Shunying Zhu ,&nbsp;Jingan Wu ,&nbsp;Xiaoyue Zhao","doi":"10.1016/j.physa.2025.130961","DOIUrl":"10.1016/j.physa.2025.130961","url":null,"abstract":"<div><div>Spatiotemporal traffic oscillations at consecutive merging bottlenecks play a critical role in the formation and amplification of congestion. A better understanding of their propagation is essential for developing effective traffic control strategies. While previous studies have primarily examined oscillations from macroscopic perspectives or in isolated bottleneck settings, the interactions between oscillations across closely spaced merging bottlenecks remain underexplored. This study addresses this gap by analyzing empirical trajectory data to investigate oscillation dynamics at a mesoscopic, lane-specific level. To accurately identify oscillation patterns, a wavelet transform method was applied to the trajectory data. The data were then aggregated using a spatiotemporal window structure. The Spatial autoregressive with autoregressive disturbances (SARAR) model, incorporating a Gaussian kernel-based spatiotemporal weights matrix, was employed to quantify the influence of both endogenous and exogenous factors. Results found that traffic oscillations exhibit a significant spatial spillover effect, whereby an existing oscillation can trigger a new oscillation in adjacent regions. However, this spatial effect is not deterministic; theoretical lag distance analysis shows that local disruptions can be absorbed if vehicles maintain stable operation for a sufficient duration (approximately 100 s in our data). Furthermore, the upstream bottleneck acts as a powerful amplifier, inducing a unique oscillation pattern. Merging events within these oscillations exhibit a distinct characteristic: both pre- and post-merge time headways remain consistently low (around 3 s). This persistent low-headway merging serves as a mechanism for cumulative disruption in acceleration and speed. This study provides a framework to characterize spatiotemporal propagation of oscillations and highlights the importance of local interactions in congested traffic flow.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"678 ","pages":"Article 130961"},"PeriodicalIF":3.1,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145011032","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}