Physica A: Statistical Mechanics and its Applications最新文献

{"title":"Efficient strategy for Parallel Minority Games","authors":"Ankith Reddy Vemula ,&nbsp;Soumyajyoti Biswas","doi":"10.1016/j.physa.2026.131373","DOIUrl":"10.1016/j.physa.2026.131373","url":null,"abstract":"<div><div>We study the parallel Minority Game, where a group of agents, each having two choices, try to independently decide on a strategy such that they stay on the minority between their own two choices. However, there are multiple such groups of agents, and some of them have common choices. This overlap brings in additional competition among the agents making the variance reduction in population fluctuation among the different choices a complex optimization problem. We study multiple stochastic strategies and find that the most efficient strategy among these is the one where the agents have just the memory of their last visit to the their alternative choice. The resulting dynamics, even though giving the lowest population variance among the strategies studied here, end up in a frozen state. However, the frozen state does not bring the variance to its lowest possible value; a situation qualitatively analogous to the spin-glass systems.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131373"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386957","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":"Threshold-controlled fractional dissipation in open quantum systems","authors":"Khushboo Rani","doi":"10.1016/j.physa.2026.131401","DOIUrl":"10.1016/j.physa.2026.131401","url":null,"abstract":"<div><div>Non-Markovian environments often exhibit power-law memory and intermittent activation, features that cannot be captured by standard Lindblad dynamics. We introduce a threshold-controlled fractional dissipation model in which decoherence is regulated by a sigmoid-type activation function driven by a set of classical control variables representing activation strength, modulation, and threshold level. Combined with a fractional power-law memory kernel, this structure allows dissipation to switch on smoothly whenever an effective activation parameter exceeds its threshold. The resulting dynamics define a controlled interpolation between unitary evolution, standard Lindblad dissipation, and fractional non-Markovian behaviour. Application to a single qubit demonstrates threshold-induced dissipation onset and power-law decoherence, capturing physical scenarios such as switching noise, feedback-driven dissipation, and intermittent environmental coupling. The framework offers a compact and physically motivated tool for studying memory-controlled quantum evolution.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131401"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387031","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":"Quantifying Iran’s endemic transition in COVID-19 through Omicron reproduction number estimates","authors":"Dorsa Macky Aleagha,&nbsp;Payam Zohari,&nbsp;Mostafa Haghir Chehreghani","doi":"10.1016/j.physa.2026.131422","DOIUrl":"10.1016/j.physa.2026.131422","url":null,"abstract":"<div><div>The emergence of the SARS-CoV-2 Omicron variant in early 2022 substantially altered COVID-19 transmission dynamics in Iran, accelerating the transition toward an endemic-like pattern. We estimated the time-varying effective reproduction number (<span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span>) in Iran from January 2022 to December 2023 using daily reported case data from the Our World in Data (OWID) repository. Four complementary estimation methods were employed: Exponential Growth (EG), Maximum Likelihood (ML), Sequential Bayesian (SB), and Time-Dependent (TD). To mitigate reporting artifacts, a seven-day rolling average was applied; missing observations were imputed via linear interpolation, and anomalous outliers were cross-checked against official epidemiological bulletins. Sensitivity analyses varied the mean generation time between 2.5 and 3.5 days. Variant-specific <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> estimates were derived for periods dominated by the BA.1 and BA.4/BA.5 Omicron subvariants using genomic surveillance data. Regional comparisons with neighboring countries (Iraq, Turkey, Armenia, Azerbaijan, Afghanistan, and Pakistan) contextualized Iran’s transmission trends. Results indicate that <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> remained persistently above the epidemic threshold of 1.0 throughout the study period, with mean values ranging from 1.27 to 1.47 across methods. The BA.1 and BA.4/BA.5 periods exhibited mean <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> values of 1.35 and 1.31, respectively, suggesting sustained community transmission despite transient short-term dips below unity. An open-source R-based toolkit is provided to support reproducible <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> estimation under real-world data constraints. These findings offer quantitative evidence of endemic-phase transmission and inform future surveillance and preparedness strategies.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131422"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387037","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":"From global to local: A transfer learning framework for municipal dengue prediction in Brazil","authors":"Werner Kristjanpoller ,&nbsp;Leonardo H.S. Fernandes ,&nbsp;Jader S. Jale ,&nbsp;Maria A.R. Silva ,&nbsp;Benjamin Miranda Tabak","doi":"10.1016/j.physa.2026.131375","DOIUrl":"10.1016/j.physa.2026.131375","url":null,"abstract":"<div><div>Dengue fever poses a growing global public health challenge, particularly in Brazil, where municipal-level forecasting is limited by high epidemiological variability and data scarcity. To address this problem, we propose a scalable deep transfer learning framework that leverages global dengue incidence data to improve short- and medium-term municipal forecasts. The approach employs CNN–LSTM architectures pre-trained on international data and fine-tuned using local information from the metropolitan regions of São Paulo, Rio de Janeiro, and Minas Gerais. Model performance is evaluated against classical statistical approaches, including Poisson, Negative Binomial, Integer-valued Conditional Heteroskedasticity, and SARIMA models, using MAPE, MAE, and MSE as complementary accuracy metrics. The results show that deep learning models substantially outperform traditional methods, with error reductions exceeding 75% in most settings. Moreover, transfer learning yields additional gains of up to 36% relative to models trained solely on local data, consistently across forecasting horizons of one to four weeks. By integrating global epidemiological patterns with local transmission dynamics, the proposed framework improves predictive robustness in data-limited municipal contexts and offers a practical tool to support early warning systems and public health decision-making.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131375"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387080","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":"Topological quantum phase transitions and multicritical caloric effects in the AI symmetry class","authors":"L.J. Ding,&nbsp;Y. Zhong","doi":"10.1016/j.physa.2026.131391","DOIUrl":"10.1016/j.physa.2026.131391","url":null,"abstract":"<div><div>Topological insulators (TIs), topological semimetals (TSMs) and topological metals (TMs) have attracted broad attention. A key challenge lies in realizing and controllably tuning these diverse topological states and transitions within a single, coherent system. Here, we propose a double coupled Su-Schrieffer-Heeger chain with time-reversal symmetry (AI class) to achieve this, wherein intrachain hopping drives topological quantum phase transitions with changing Zak phase and showing different types of critical TSMs, while interchain hopping drives a Wilson insulator-metal transition without altering the underlying topology. We obtain a rich phase diagram segmented by topological and Wilson critical lines intersecting at a multicritical point, consisting of two TIs (TI1, TI2) and two TMs (TM1, TM2). TI1 and TM1 share the same topology, as do TI2 and TM2. Meanwhile, thermal Drude weight used as a diagnostic tool at low temperatures, shows sharp peaks or dips at phase boundaries, successfully mapping the entire phase diagram and characterizing the low-lying excitations. Furthermore, an optimal cooling path is found: by tuning interchain hopping along the topological critical line, one can obtain a significant inverse caloric effect near the multicritical point at low temperatures with large entropy and temperature change as well as high efficiency factor. It offers a promising solid-state cooling mechanism for achieving ultra-low temperatures in quantum technologies.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131391"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387032","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 feedback and nonlinear nuclear spin dynamics in driven NV center ensembles","authors":"A.-B.A. Mohamed ,&nbsp;A.S.A. Alghwali ,&nbsp;E.K. Jaradat ,&nbsp;Hazrat Ali","doi":"10.1016/j.physa.2026.131399","DOIUrl":"10.1016/j.physa.2026.131399","url":null,"abstract":"<div><div>Nitrogen vacancy (NV) centers in diamond are a key platform for solid-state quantum technologies and precision sensing. In dense ensembles the surrounding nuclear and electronic spin environment cannot be treated as a purely passive noise source: the driven NV spins polarize their bath, and the resulting Overhauser field feeds back on the NV dynamics. Starting from the spin-1 NV Hamiltonian with hyperfine couplings, we use a Schrieffer–Wolff transformation to derive drive- and detuning-dependent nuclear flip rates near Hartmann–Hahn and level-anticrossing conditions. Combining these rates with optical Bloch steady states for the NV spin, we obtain closed mean-field equations for the nuclear polarization and electronic inversion. Linear stability analysis yields a dimensionless feedback gain that delineates regimes where the weakly polarized bath is stable and where it self-organizes into strongly polarized states. Within this framework we compute detuning- and drive-dependent nuclear polarization, ODMR linewidths and Hahn-echo coherence times, and construct a stability map in the drive–detuning plane that identifies feedback-active regions with substantial linewidth narrowing and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> enhancement accessible to current NV-ensemble experiments.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131399"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387035","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":"Study on dynamic magnetic behaviors and magnetocaloric effect in double-layer MXene-like structure with mixed spins","authors":"Kai-Le Shi ,&nbsp;Zhong-Qian Su ,&nbsp;Wei Jiang","doi":"10.1016/j.physa.2026.131403","DOIUrl":"10.1016/j.physa.2026.131403","url":null,"abstract":"<div><div>Based on Monte Carlo simulation, dynamic magnetic behaviors and the magnetocaloric effect of the double-layer MXene-like structure have been studied. The Ising model is employed to describe a double-layer MXene-like structure. Order parameters, susceptibility, and internal energy are discussed with various parameters. Additionally, hysteresis loops and coercivity are also depicted. We find that the exchange interaction, the amplitude, and the temperature are sensitive to the hoop number and the coercivity of the system. The presence of a bias field brings about order, whereas the oscillating magnetic field induces disorder. Besides, we also give the magnetic entropy changes and RCP of the double-layer MXene-like structure. These results have extensive application in spintronics, magnetic storage, and magnetic refrigeration.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131403"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387078","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":"Morphological effects on bacterial Brownian motion: Validation of a chiral two-body model","authors":"Baopi Liu ,&nbsp;Bowen Jin ,&nbsp;Lu Chen ,&nbsp;Ning Liu","doi":"10.1016/j.physa.2026.131423","DOIUrl":"10.1016/j.physa.2026.131423","url":null,"abstract":"<div><div>We systematically investigate how flagellar morphology governs the stability of bacterial Brownian motion, evaluating the effectiveness of a simplified chiral two-body model. This model, which effectively captures the specific bacterial morphology and significantly reduces computational cost, is used for simulating bacterial Brownian motion. Our results demonstrate that the model accurately reproduces the Brownian motion of bacteria for contour lengths <span><math><mrow><mi>Λ</mi><mo>≥</mo><mn>5</mn><mo>.</mo><mn>0</mn></mrow></math></span> <span><math><mi>μ</mi></math></span>m, helix radii <span><math><mrow><mn>0</mn><mo>.</mo><mn>2</mn><mo>≤</mo><mi>R</mi><mo>≤</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span> <span><math><mi>μ</mi></math></span>m, and pitch angles <span><math><mrow><mi>π</mi><mo>/</mo><mn>6</mn><mo>≤</mo><mi>θ</mi><mo>≤</mo><mn>2</mn><mi>π</mi><mo>/</mo><mn>9</mn></mrow></math></span>. We find that the translational and rotational velocities of bacteria depend linearly on the motor rotation rate, independent of dynamic viscosity. Increasing helix radius and contour length leads to more elongated trajectories and enhances their linearity. Furthermore, longer contour lengths improve the stability of the bacterial forward motion. Collectively, these findings demonstrate the essential role of flagella in stabilizing bacterial Brownian motion and confirm the effectiveness of the chiral two-body model for simulating this phenomenon.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131423"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386959","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":"Higher-order interactions with payoff weighting promote cooperation in public goods on simplicial complexes","authors":"Zhongfu Liu ,&nbsp;Jinlong Ma","doi":"10.1016/j.physa.2026.131413","DOIUrl":"10.1016/j.physa.2026.131413","url":null,"abstract":"<div><div>Cooperation is commonly observed in social and natural systems. Interaction topology is recognized as a catalyst for cooperation, and most work has focused on pairwise interactions. However, higher-order interactions among three or more participants are widespread in real-world, and pairwise models do not fully capture them. In this work, we improve the public goods game model on simplicial complexes that combines higher-order interactions, nonlinear synergy parameters, and payoff weighting. This model allows the payoff weights on 1-simplices and 2-simplices to be adjustable. The effects of the nonlinear synergy parameter <span><math><mi>ω</mi></math></span>, the 2-simplex fraction <span><math><mi>P</mi></math></span>, and the weighting coefficients <span><math><mi>λ</mi></math></span> and <span><math><mi>β</mi></math></span> on cooperation are investigated through Monte Carlo simulations. On the simplicial complexes, the results indicate that higher-order structures alone do not promote cooperation. When nonlinear synergy and higher-order interactions work together, a significant reduction in the cooperation threshold and a substantial expansion of the cooperation region are observed. Various allocations of the payoff weight parameter have a moderating effect on the cooperative evolutionary process. Furthermore, strategic coherence of multi-party interactions in a network can facilitate cooperative diffusion.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131413"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387036","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":"Corrigendum to “Combined use of ‘‘two-step’’ and ‘‘field-theoretic’’ renormalization group theories for deterministic partial differential equations” [Phys. A 687 (2026) 131362]","authors":"Ko Okumura","doi":"10.1016/j.physa.2026.131406","DOIUrl":"10.1016/j.physa.2026.131406","url":null,"abstract":"","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"688 ","pages":"Article 131406"},"PeriodicalIF":3.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386912","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}