IF 1.7 4区物理与天体物理

International Journal of Theoretical Physics Pub Date : 2025-09-08 DOI: 10.1007/s10773-025-06126-y

Efe Türbedar, Ferhat Nutku

引用次数: 0

Characteristics of non-specular meteor trail echoes detected with Gadanki MST radar Gadanki MST雷达探测的非镜面流星轨迹回波特征

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-09-08 DOI: 10.1007/s12036-025-10093-5

K. Chenna Reddy

引用次数: 0

Predicting CME speed at 20(R_{odot }) using machine learning approaches 使用机器学习方法预测CME速度为20 (R_{odot })

IF 1.8 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2025-09-08 DOI: 10.1007/s10509-025-04482-z

M. Hegde

{"title":"Predicting CME speed at 20(R_{odot }) using machine learning approaches","authors":"M. Hegde","doi":"10.1007/s10509-025-04482-z","DOIUrl":"10.1007/s10509-025-04482-z","url":null,"abstract":"<div>Coronal mass ejections (CMEs) are significant drivers of space weather, and accurately predicting their propagation speed is crucial for mitigating their impact on Earth’s environment. In this study, we leverage machine learning techniques to model and predict CME speed at 20(R_{odot }) utilizing data from the Coordinated Data Analysis Workshop catalog. We considered data from Solar Cycles 23 and 24, divided into their rising, maxima, decline, and minima phases, to train multivariate linear regression, Random Forest, and XGBoost machine learning models aimed at predicting CME speeds at 20(R_{odot }). The machine learning models use linear speed, acceleration, width, and kinetic energy as input features to estimate CME speeds at 20(R_{odot }). Our results indicate that Random Forest and XGBoost models significantly outperform linear regression model across all datasets, achieving high R2 values (≈0.97) and low relative errors (6%) for most phases, especially during high solar activity. Feature importance analysis identifies CME linear speed and acceleration as the dominant predictors of CME speed at 20(R_{odot }). This result is consistent with physical models, which describe CME propagation as being influenced primarily by initial speed and the drag force acting through acceleration or deceleration in the interplanetary medium. The trained models were applied to available events from Solar Cycle 25, to predict CME speeds at 20(R_{odot }). The predicted values showed very good agreement with the actual speeds reported in the CDAW catalog. This successful application demonstrates the models’ generalizability and potential for forecasting future CME dynamics. Furthermore, such data-driven predictions can complement physics-based models—such as the Drag-Based Model—by providing reliable speed estimates at specific heliocentric distances, thereby enhancing the accuracy of space weather forecasts.</div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"370 9","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007917","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}

引用次数: 0

Observations of the Occultation of the Star TYC 1318-01031-1 by Asteroid (52) Europa on September 9, 2020 2020年9月9日欧罗巴小行星（52）掩星TYC 1318-01031-1的观测

IF 0.7 4区物理与天体物理

Kinematics and Physics of Celestial Bodies Pub Date : 2025-09-08 DOI: 10.3103/S0884591325050046

V. V. Kleshchonok, V. L. Karbovsky, V. I. Kashuba, O. V. Angelsky, M. V. Lashko

{"title":"Observations of the Occultation of the Star TYC 1318-01031-1 by Asteroid (52) Europa on September 9, 2020","authors":"V. V. Kleshchonok, V. L. Karbovsky, V. I. Kashuba, O. V. Angelsky, M. V. Lashko","doi":"10.3103/S0884591325050046","DOIUrl":"10.3103/S0884591325050046","url":null,"abstract":"This article presents the results of observations and data processing of the occultation of star TYC 1318-01031-1 by asteroid (52) Europa conducted at multiple sites. Data from both professional astronomers and experienced amateur observers are utilized. Professional observations have been conducted with an 80-cm diameter telescope equipped with a QHY174M GPS camera, which provides precise UTC time-stamping for each exposure via its integrated GPS receiver. Amateur observations have been carried out with various telescopes and cameras, with the data recorded in video format. The video recordings were processed using a unified methodology to derive the photometric occultation light curve. Ingress and egress times of the occultation at each observing site are determined from the extracted photometric light curves of TYC 1318-01031-1. A proprietary method is applied to combine occultation chords from geographically dispersed sites where observations have been acquired independently [1]. Subsequent processing employs the proposed combination method to compute each site’s offset from the occultation path centerline. Chords of asteroid (52) Europa for each observing site are then calculated from the measured ingress and egress times of the occultation. Calculated asteroid chords are compared to the 3D shape model of the asteroid from the Database of Asteroid Models from Inversion Techniques (DAMIT). This approach yields strong validation of the technique and demonstrates that amateur observations, taking into account potential UTC time-stamping errors, can be used to reconstruct asteroid shapes. The results also confirm that the shape and dimensions of asteroid (52) Europa in the DAMIT database are accurate.","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"41 5","pages":"203 - 208"},"PeriodicalIF":0.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007938","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}

引用次数: 0

On-Chip Passive Optical Spectrometer with Multimode Photonic Devices 带有多模光子器件的片上无源光谱仪

IF 7 1区物理与天体物理

ACS Photonics Pub Date : 2025-09-08 DOI: 10.1021/acsphotonics.5c00805

Long Zhang, Shihan Hong, Da Lv, Zejie Yu, Daoxin Dai

{"title":"On-Chip Passive Optical Spectrometer with Multimode Photonic Devices","authors":"Long Zhang, Shihan Hong, Da Lv, Zejie Yu, Daoxin Dai","doi":"10.1021/acsphotonics.5c00805","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00805","url":null,"abstract":"On-chip optical spectrometers are widely regarded as a highly promising solution for portable and wearable sensing applications. In particular, optical spectrometers are often preferred to operate passively without the need for external power for tuning, thereby significantly reducing system complexity and power consumption. This is vital for promoting the widespread adoption of spectroscopic technology in resource-constrained scenarios demanding ultralow power consumption. In addition, achieving on-chip spectrometers with both a large bandwidth and high resolution remains a significant challenge, particularly when the physical channel number is limited. In this work, we propose and demonstrate a high-performance on-chip passive spectrometer leveraging advanced multimode photonics. The spectral information is decorrelated through stochastic mode generation, coupling/mixing, wavelength-selective resonance, and demultiplexing enabled by multiple distinct modes (e.g., the TE0, TE1, and TE2 mode) in a spiraled multimode waveguide system, significantly enhancing transmission matrix decorrelation across a broad bandwidth. Experimentally, it is demonstrated that the present optical spectrometer successfully achieves a remarkable resolution of 10 pm and a broad bandwidth of 80 nm with only 36 synthetic physical channels. This performance corresponds to a wavelength-channel capacity of 8 × 103 and a reconstructive compression ratio of 222, setting a new benchmark for on-chip passive optical spectrometers reported to date.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"40 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009108","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}

引用次数: 0

The two-Higgs doublet model beyond tree-level: a gauge-invariant formalism 树级以上的双希格斯双重态模型：一种标准不变的形式主义

IF 5.5 1区物理与天体物理

Journal of High Energy Physics Pub Date : 2025-09-08 DOI: 10.1007/JHEP09(2025)065

T. Guerandel, M. Maniatis, L. Sartore, I. Schienbein

{"title":"The two-Higgs doublet model beyond tree-level: a gauge-invariant formalism","authors":"T. Guerandel, M. Maniatis, L. Sartore, I. Schienbein","doi":"10.1007/JHEP09(2025)065","DOIUrl":"10.1007/JHEP09(2025)065","url":null,"abstract":"Employing the gauge-invariant formalism in the two-Higgs-doublet model (THDM) offers profound insights into the model’s fundamental structure. A specific set of gauge-invariant bilinear combinations, constructed from the Higgs doublets, establishes a one-to-one correspondence between the components of the doublet fields and real-valued bilinears. This formalism provides a compact and consistent framework to study various aspects of the THDM, including stability, electroweak symmetry breaking, basis transformations, and general symmetries of the Higgs potential.Recently, the bilinear formalism has been extended beyond the Higgs potential to encompass the full THDM, including the gauge and Yukawa sectors, all in gauge-invariant terms. In this work, we advance the formalism further by incorporating quantum corrections. Specifically, we show how bilinears, combined with the ħ-expansion, can be used to compute one-loop corrections. We provide concise, gauge-invariant expressions for these corrections, which are directly applicable to the THDM.","PeriodicalId":635,"journal":{"name":"Journal of High Energy Physics","volume":"2025 9","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/JHEP09(2025)065.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145011555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

IRAS 22272+5435 (V354 Lac): Multicolor Photometry of a Variable Carbon-rich Post-AGB Star and a Dust Formation Episode IRAS 22272+5435 (V354 Lac): agb后富碳变星和尘埃形成事件的多色光度测定

IF 0.8 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2025-09-08 DOI: 10.1134/S1063773725700240

N. P. Ikonnikova, V. I. Shenavrin, G. V. Komissarova, M. A. Burlak

引用次数: 0

Exploring the Dynamics of Dark Energy in (boldsymbol{f(Q,C)}) Gravity: A Comprehensive Analysis Using Cosmological Datasets 探索(boldsymbol{f(Q,C)})重力中的暗能量动力学：使用宇宙学数据集的综合分析

IF 0.8 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2025-09-08 DOI: 10.1134/S1063773725700203

Amit Samaddar, S. Surendra Singh

引用次数: 0

On-shell Lagrangians as total derivatives and the generalized Komar charge 作为全导数的壳层拉格朗日量和广义科马尔电荷