物理与天体物理最新文献

{"title":"Mamba time series forecasting with uncertainty quantification.","authors":"Pedro Pessoa, Paul Campitelli, Douglas P Shepherd, S Banu Ozkan, Steve Pressé","doi":"10.1088/2632-2153/adec3b","DOIUrl":"10.1088/2632-2153/adec3b","url":null,"abstract":"<p><p>State space models, such as Mamba, have recently garnered attention in time series forecasting (TSF) due to their ability to capture sequence patterns. However, in electricity consumption benchmarks, Mamba forecasts exhibit a mean error of approximately 8%. Similarly, in traffic occupancy benchmarks, the mean error reaches 18%. This discrepancy leaves us to wonder whether the prediction is simply inaccurate or falls within error given spread in historical data. To address this limitation, we propose a method to quantify the predictive uncertainty of Mamba forecasts. To achieve this, we propose a dual-network framework based on the Mamba architecture for probabilistic forecasting, where one network generates point forecasts while the other estimates predictive uncertainty by modeling variance. We abbreviate our tool, Mamba with probabilistic TSF, as Mamba-ProbTSF and the code for its implementation is available on GitHub https://github.com/PessoaP/Mamba-ProbTSF. Evaluating this approach on synthetic and real-world benchmark datasets, we find Kullback-Leibler divergence between the learned distributions and the data-which, in the limit of infinite data, should converge to zero if the model correctly captures the underlying probability distribution-reduced to the order of 10^-3 for synthetic data and 10^-1 for real-world benchmark. We find that in both the electricity consumption and traffic occupancy benchmark, the true trajectory stays within the predicted uncertainty interval at the two-sigma level about 95% of the time. We further compare Mamba-ProbTSF against leading probabilistic forecast methods, DeepAR and ARIMA, and show that our method consistently achieves lower forecast errors while offering more reliable uncertainty quantification. We end with a consideration of potential limitations, adjustments to improve performance, and considerations for applying this framework to processes for purely or largely stochastic dynamics where the stochastic changes accumulate as observed, for example, in pure Brownian motion or molecular dynamics trajectories.</p>","PeriodicalId":33757,"journal":{"name":"Machine Learning Science and Technology","volume":"6 3","pages":"035012"},"PeriodicalIF":6.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12281171/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144699735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Beyond Euclid: an illustrated guide to modern machine learning with geometric, topological, and algebraic structures.","authors":"Mathilde Papillon, Sophia Sanborn, Johan Mathe, Louisa Cornelis, Abby Bertics, Domas Buracas, Hansen J Lillemark, Christian Shewmake, Fatih Dinc, Xavier Pennec, Nina Miolane","doi":"10.1088/2632-2153/adf375","DOIUrl":"10.1088/2632-2153/adf375","url":null,"abstract":"<p><p>The enduring legacy of Euclidean geometry underpins classical machine learning, which, for decades, has been primarily developed for data lying in Euclidean space. Yet, modern machine learning increasingly encounters richly structured data that is inherently non-Euclidean. This data can exhibit intricate geometric, topological and algebraic structure: from the geometry of the curvature of space-time, to topologically complex interactions between neurons in the brain, to the algebraic transformations describing symmetries of physical systems. Extracting knowledge from such non-Euclidean data necessitates a broader mathematical perspective. Echoing the 19th-century revolutions that gave rise to non-Euclidean geometry, an emerging line of research is redefining modern machine learning with non-Euclidean structures. Its goal: generalizing classical methods to unconventional data types with geometry, topology, and algebra. In this review, we provide an accessible gateway to this fast-growing field and propose a graphical taxonomy that integrates recent advances into an intuitive unified framework. We subsequently extract insights into current challenges and highlight exciting opportunities for future development in this field.</p>","PeriodicalId":33757,"journal":{"name":"Machine Learning Science and Technology","volume":"6 3","pages":"031002"},"PeriodicalIF":4.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12315666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144776367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Structural, Electrical, Magnetic, and Electrochemical Properties of Mg0.5MnxZn0.5-xFe2O4 Nanoferrites","authors":"Nancy,&nbsp;Preeti Thakur,&nbsp;Ritesh Verma,&nbsp;Rakesh Kumar,&nbsp;Yassine Slamani,&nbsp;Atul Thakur","doi":"10.1007/s10948-025-07045-z","DOIUrl":"10.1007/s10948-025-07045-z","url":null,"abstract":"<div><p>Herein, manganese-doped magnesium zinc ferrite nanoparticles were synthesized using co-precipitation method. X-ray diffraction (XRD) analysis of the ferrite samples showed a pure spinel phase (Mg_0.5Mn_xZn_0.5-xFe₂O₄) with a cubic spinel structure where crystallite size was observed in the range of 13 to 18 nm, whereas the lattice parameter increased from 7.678 to 7.726 Å with an increase in Mn²⁺ ion concentration. The increase in crystallite size was coupled with a reduction in the lattice strain, which ranged from 0.020 to 0.007. FTIR studies showed that when Mn²⁺ ion doping increased, the band location in the high-frequency band region decreased from 565.182 to 418.779 cm⁻¹. Five Raman active vibrational modes at 180–700 cm⁻¹ were visible in the Raman spectra. With low coercivity, the nanoferrites displayed excellent magnetization values from 24.44 to 42.11 emu/g. A single semicircular arc in the Cole–Cole plot described grain dominance. According to the impedance spectrometry plot, composition <i>x</i> = 0.4 exhibited the highest ac conductivity, 0.000137 S/cm, at 10 MHz frequency, and the lowest tangent loss value, 0.553, at 1.12 MHz frequency for <i>x</i> = 0.0 composition. As the doping level increased, the ac conductivity increased as well. None of the samples exhibit Debye behavior, as indicated by the wide range of conductivity values. The substitution of manganese ions not only affected the structural characteristics of the nanoferrites but also significantly impacted their electrical conductivity from 0.34 × 10⁻⁴ to 1.3 × 10⁻⁴ S/cm. These changes made Mn-substituted Mg–Zn nanoferrites promising candidates for various applications in magnetic devices and energy storage systems.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Orthogonal design of bioinspired butterfly-wing microstructures for enhanced anti-reflection performance","authors":"Bing Zhong ,&nbsp;Xinbo Zhou ,&nbsp;Quan Gu ,&nbsp;Jie Ding ,&nbsp;Chao Zhang ,&nbsp;Hefa Zhu ,&nbsp;Zhong Wang","doi":"10.1016/j.optlastec.2025.113840","DOIUrl":"10.1016/j.optlastec.2025.113840","url":null,"abstract":"<div><div>To enhance the mid-infrared (MIR) antireflection performance of material surfaces, three bioinspired MIR-antireflective structures were designed based on butterfly wing microstructures and fabricated. Reflectance served as the response metric in an orthogonal experimental design to optimize structural parameters and evaluate high-temperature service stability. Results demonstrate that the dominant factors governing antireflection efficacy, in descending order of significance, are: lateral dimension (diameter/side length/width), periodicity, depth, and structure type. The optimal configuration achieving minimal reflectance (5.40 %) is a bioinspired concave groove structure with depth 260 μm, width 90 μm, and period 100 μm. The synergistic combination of structural geometry, dimensional parameters, and processing induced defects underpins the high antireflection performance. The optimized structure exhibits robust high-temperature service stability.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113840"},"PeriodicalIF":5.0,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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-Rotor unmanned aerial vehicle Rotor-Strut interaction tonal noise","authors":"Ruixuan He ,&nbsp;Michael J. Kingan ,&nbsp;Xinjing Wang ,&nbsp;Xianghao Kong ,&nbsp;Huachen Zhu","doi":"10.1016/j.apacoust.2025.111054","DOIUrl":"10.1016/j.apacoust.2025.111054","url":null,"abstract":"<div><div>A frequency domain method is presented to predict rotor-strut interaction tonal noise. The method directly relates each harmonic of tonal noise to the unsteady loading harmonics on the rotor/strut surfaces using the frequency-domain Green’s function. The formulation shows that each harmonic of rotor tonal noise is composed of contributions from all harmonics of rotor loading, whereas each harmonic of strut tonal noise is produced exclusively by the corresponding harmonic of strut loading. Computational Fluid Dynamics (CFD) simulations are used to predict the unsteady loading on a practical multi-rotor unmanned aerial vehicle (UAV) rotor-strut system. This loading is used as input to the frequency-domain method and the results are compared with experimental measurements, showing reasonable agreement to within 3 dB at most observer positions. It is observed that the rotor-strut interaction generates an acoustic pressure impulse, which is weakened as the rotor-strut spacing increases. Additionally, the noise radiated from the loading sources on the struts is found to vary significantly with azimuthal angle. Using unsteady CFD simulations to predict the unsteady loading is time-consuming and ill-suited for design process applications. Therefore, an analytical model is developed to quickly estimate this unsteady loading. The analytical model is applied to a practical rotor-strut system, and the resulting noise radiation is calculated using the frequency-domain method. The predictions are found to be in reasonable agreement (overall sound pressure level within 3 dB) with the numerical simulations and experimental measurements.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"242 ","pages":"Article 111054"},"PeriodicalIF":3.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Wear behaviors of laser-directed energy deposited Inconel 625 alloys-based composite coating by different oscillating laser paths","authors":"Kaiming Wang ,&nbsp;Zeng Yi ,&nbsp;Zibo Song ,&nbsp;Yongle Hu ,&nbsp;Xiaotong Pang ,&nbsp;Jian Zhang ,&nbsp;Xixi Ji ,&nbsp;Jingzhong Fang ,&nbsp;Pengfei Wu ,&nbsp;Mingjun Zhang ,&nbsp;Peng Zhang ,&nbsp;Yonggang Tong ,&nbsp;Jian Gu","doi":"10.1016/j.optlastec.2025.113900","DOIUrl":"10.1016/j.optlastec.2025.113900","url":null,"abstract":"<div><div>This study investigated the microstructure evolution and wear mechanism of Inconel 625 alloy manufactured by oscillating laser-directed energy deposition (LDED) under various oscillation paths. The results reveal that laser oscillation effectively suppresses epitaxial growth tendencies while promoting the columnar-to-equiaxed transition (CET) of dendrites. The infinite oscillating laser path induces reduced dilution rate and aspect ratio, generating uniformly refined equiaxed grains that simultaneously enhance microhardness and improve wear resistance across both room-temperature and high-temperature conditions. The wear mechanisms indicated that room-temperature conditions predominantly exhibited abrasive and adhesive wear, complemented by minor oxidative wear. In contrast, the high-temperature wear behavior undergoes a transformation into oxidation dominated and adhesive wear mechanisms.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113900"},"PeriodicalIF":5.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Imaging detection and feature reconstruction of cylindrical surface components internal defects based on laser ultrasonic techniques","authors":"Yu Peng ,&nbsp;Xiaokai Wang ,&nbsp;Shutong Dai ,&nbsp;Kangwen Huang ,&nbsp;Chaoshan Ren ,&nbsp;Yan Zeng ,&nbsp;Zhixiong Han ,&nbsp;Linlin Gui","doi":"10.1016/j.optlastec.2025.113927","DOIUrl":"10.1016/j.optlastec.2025.113927","url":null,"abstract":"<div><div>Internal pores, cracks at different angles, and other internal defects have varying degrees of influence on the fatigue performance and service safety of curved surface components such as machine tool bearings and train wheels. Therefore, the imaging detection and feature reconstruction of internal defects in curved surface components are of vital importance for identifying the types and morphologies of defects. Laser ultrasonic testing enables full-coverage internal defect inspection, particularly effective for curved-surface components. When combined with advanced imaging algorithms, this technique achieves accurate spatial quantification and volumetric reconstruction of subsurface flaws. This study introduces a polar coordinate-based synthetic aperture focusing technique (SAFT) to improve imaging efficiency and quality. Simulation models were developed to replicate the B-Scan process of laser ultrasonic interactions with defects in curved components, generating B-Scan characteristic images for various defect types. The polar coordinate-based SAFT considering directionality in polar coordinates was used to reconstruct the defects in the simulation model. A laser ultrasonic rotational scanning system was employed to conduct B-Scan experiments on samples containing pre-fabricated defects (e.g., pore, porosity, horizontal crack, 45° crack, and vertical crack). The proposed algorithm was then applied to reconstruct these defects. The reconstructed hole defects exhibited minimal positional errors, with a maximum deviation of 0.564 mm. Crack defects showed variations in angular and length errors, with maximum angular and length deviations of 3.129° and 2.198 mm, respectively. The results demonstrate that laser ultrasonics enables precise localization and quantitative assessment of internal defects within curved structural components.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113927"},"PeriodicalIF":5.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Minimally complex fuzzy wormhole models in Einstein-Cartan theory of gravity","authors":"Z. Yousaf ,&nbsp;M. Rizwan ,&nbsp;Mohammad Alshammari ,&nbsp;Othman Abdullah Almatroud ,&nbsp;Saleh Alshammari ,&nbsp;M. Mossa Al-sawalha","doi":"10.1016/j.dark.2025.102082","DOIUrl":"10.1016/j.dark.2025.102082","url":null,"abstract":"<div><div>In this work, we explore the possibility of constructing minimally complex wormhole geometries supported by fuzzy dark matter, framed within the Einstein-Cartan gravity model. By using the realistic Einasto density profile to model dark matter haloes, we reveal how dark matter distributions can form and affect wormhole structures. The matter content is an anisotropic fluid with Weyssenhoff spin contributions, effectively including quantum spin effects in the relativistic anisotropic energy–momentum tensor. The wormhole shape function is determined by solving the field equations and the Einasto profile. We then probe further into the dark matter’s role in dictating important physical properties of the wormhole, such as the complexity factor, equation of state, equilibrium status, energy limits, and active gravitational mass. To further complement our results, a detailed graphical analysis is included, illustrating how dark matter can dictate the geometry and physical feasibility of such extreme spacetime geometries.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102082"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Cascaded Metasurfaces Enabled Versatile Beam Steering From Propagating Waves to Surface Waves","authors":"Shibin Jiang, Peng Zheng, Guanxing Zang, Zhirui Zeng, Xueyang Luo, Weiming Zhu","doi":"10.1002/lpor.202500393","DOIUrl":"https://doi.org/10.1002/lpor.202500393","url":null,"abstract":"","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"35 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145056946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Asymmetrically Nonlinear Generation of Optical Orbital Angular Momentum via Cooperation of Bragg Diffraction and Birefringent Phase Matching","authors":"Xinyu Liu, Chun Chang, Yuntao Mo, Dingwei Liu, Dan Wei, Juntao Li, Dunzhao Wei, Xuehua Wang","doi":"10.1002/lpor.202501656","DOIUrl":"https://doi.org/10.1002/lpor.202501656","url":null,"abstract":"","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"133 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145056947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}