物理最新文献

{"title":"Fermions in (left( 1+2right))-dimensions modified by nonminimal coupling and its applications to condensed matter physics","authors":"J. A. A. S. Reis,&nbsp;L. Lisboa-Santos,&nbsp;Fabiano M. Andrade,&nbsp;Frankbelson dos S. Azevedo,&nbsp;Edilberto O. Silva","doi":"10.1140/epjp/s13360-025-06698-y","DOIUrl":"10.1140/epjp/s13360-025-06698-y","url":null,"abstract":"<div><p>Fermions in two-dimensional space, commonly called <span>((1+2))</span>-dimensional fermions, exhibit intriguing and distinctive characteristics that distinguish them from their higher-dimensional counterparts. This paper offers a comprehensive theoretical examination of planar fermionic systems, presenting novel findings by incorporating nonminimal coupling. Our analysis includes the computation of the non-relativistic limit up to second-order corrections in the Dirac equation. We also explore the Schrödinger equation under the influence of a harmonic potential and an electric field. Furthermore, we investigate how the coupling parameter affects physical properties relevant to condensed matter systems. Our results demonstrate that this parameter significantly impacts electronic properties and Hall conductivity. The interplay between an external electric field and the coupling parameter also influences energy levels and the system’s polarizability. These findings underscore the novel effects of including nonminimal coupling in wave equations, offering new insights into the physics of coupled systems.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832317","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":"Spark-based Alzheimer’s disease classification using hybrid spike Google-deep CNN-SEViT model","authors":"S. L. Abhaya,&nbsp;T. Dhiliphan Rajkumar","doi":"10.1140/epjp/s13360-025-06673-7","DOIUrl":"10.1140/epjp/s13360-025-06673-7","url":null,"abstract":"<div><p>Alzheimer's disease (AD) constitutes a neurological disorder predominantly affecting the geriatric population. It ranks as the fourth principal cause of death globally, following cardiovascular diseases, various malignancies, and cerebral hemorrhages. The pathology of Alzheimer’s leads to the degeneration of neural tissues and the demise of neurons across the cerebral cortex, thereby precipitating significant memory impairment in individuals and adversely affecting their capacity to accomplish regular activities, including writing, verbal communication, and reading. In recent decades, neuroimaging modalities have been increasingly harnessed to delineate the characteristics of AD through utilization of Machine Learning (ML) approaches, thus providing promising avenues for personalized diagnostic and prognostic assessments. More recently, Deep Learning (DL), as a nascent paradigm within the realm of ML, has witnessed substantial advancements in field of medical imaging. A more comprehensive approach is required that can accommodate big data in AD research due to the growing size of multi-modalities. This research generates a method for classification of AD using DL in spark framework. The preprocessing stage includes realignment, normalization and smoothing executed in a slave set. After preprocessing, feature extraction phase is achieved on preprocessed image in another slave set using Gold Rush Optimizer (GRO)-based VGG-16. These extracted features are then sent to master, where the Proposed SpikeGoogle- Deep Convolutional Neural Network- Squeeze-and-Excitation Vision Transformer (SpikeGoogle-DeepCNN-SEViT) model is created by combining SpikeGoogle, Deep CNN and SEViT for AD classification. The proposed SpikeGoogle-DeepCNN-SEViT model classifies the data into four classes: Mild Demented, Moderate Demented, Non-Demented, and Very Mild Demented. Experimental evidence highlights that Proposed SpikeGoogle-DeepCNN-SEViT showed higher performance compared to conventional strategies with 95.7% accuracy, 97.5% of sensitivity and 95.3% of specificity.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832322","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":"Dynamical analysis and exact soliton solutions of the truncated M-fractional Gardner–Kawahara model","authors":"Muhammad Raheel,&nbsp;Asim Zafar,&nbsp;Jian Guo Liu","doi":"10.1007/s12043-025-02969-6","DOIUrl":"10.1007/s12043-025-02969-6","url":null,"abstract":"<div><p>This research reveals the novel types of exact wave solutions of the nonlinear Gardner–Kawahara (G–K) model in the concept of truncated M-fractional derivative. The G-K model, which is also called the extended Korteweg–de Vries (KdV) model, explains the solitary wave propagation in media, notation in plasmas, notation in shallow-water waves along surface tension and notation of magneto-acoustic waves. For our purpose, two techniques, the unified and the Sardar sub-equation techniques are applied. As a result, new types of exact wave solitons having periodic, dark–bright, periodic, kink are obtained. Some of the obtained solutions are represented through two- and three-dimensional and contour plots. The effect of the truncated M-fractional derivative (TMFD) is explained by plots. Stability of a concerned equation is checked by applying stability analysis. Moreover, the modulation instability analysis of the governing equation is also performed, which proves that the model and the obtained results are stable as well as exact.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"99 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832153","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":"Diagnosing chaos in a periodically driven Ising model with a ramping field via out-of-time-order correlation saturation","authors":"Rohit Kumar Shukla,&nbsp;Gaurav Rudra Malik,&nbsp;S. Aravinda,&nbsp;Sunil Kumar Mishra","doi":"10.1140/epjb/s10051-025-01021-1","DOIUrl":"10.1140/epjb/s10051-025-01021-1","url":null,"abstract":"<p>The dynamic region of out-of-time-ordered correlators (OTOCs) serves as a powerful indicator of chaos in classical and semiclassical systems, capturing the characteristic exponential growth. However, in spin systems, the dynamic region of OTOCs does not reliably quantify chaos as both integrable and chaotic systems display similar behavior. Instead, we utilize the saturation behavior of OTOCs to differentiate between chaotic and integrable regimes. In integrable systems, the saturation region of OTOCs exhibits oscillatory behavior, while in chaotic systems, it shows a stable saturation. To evaluate this distinction, we investigate a time-dependent Ising spin system subjected to a linearly ramping transverse field, analyzing both integrable (without longitudinal field) and non-integrable (with longitudinal field) scenarios. This setup accelerates system ergodicity due to the introduction of an additional time scale within the system, enhancing chaotic dynamics in the non-integrable regime, and provides a compelling model for studying the interplay between integrability and chaos in quantum systems. To further support our findings, we investigate the level spacing distribution of time-dependent unitary operators, which effectively distinguishes chaotic from regular regions in our system and corroborates the results obtained from the saturation behavior of the OTOC. Additionally, we calculate a metric for the normalized Fourier spectrum of the OTOC which is dependent on the number of frequency components present to gain insights into the observed oscillations and its dependence on the ramping field.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 8","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-01021-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Extraction of low-mass diffractive cross section from the discrepancy between ATLAS and TOTEM total cross sections","authors":"Per Grafström,&nbsp;Rafał Staszewski","doi":"10.1140/epjc/s10052-025-14602-2","DOIUrl":"10.1140/epjc/s10052-025-14602-2","url":null,"abstract":"<div><p>At the LHC, two experiments – ATLAS and TOTEM – measure the total proton–proton cross section. Unfortunately, a significant discrepancy, persisting at different collision energies, is observed between the values reported by the two groups. This paper considers the hypothesis that this tension is predominantly driven by the assumption about the low-mass diffraction used in one of the measurement methods. It is shown that in such a case it is possible to extract the low-mass diffraction cross section from measurements of ATLAS and TOTEM. The results are compared with other data-driven estimates, showing better agreement than the original assumption.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 8","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14602-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832151","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":"A parton shower consistent with parton densities at LO and NLO: Pdf2Isr","authors":"H. Jung,&nbsp;L. Lönnblad,&nbsp;M. Mendizabal,&nbsp;Sara Taheri Monfared","doi":"10.1140/epjc/s10052-025-14595-y","DOIUrl":"10.1140/epjc/s10052-025-14595-y","url":null,"abstract":"<div><p>We present a method for obtaining an initial-state parton shower model where the (backward) evolution fully consistent with the (forward) evolution of the collinear parton density used. As a proof-of-concept we use parton densities obtained with the parton branching (PB) approach, and modify the default initial-state shower in <span>Pythia</span>8 with this method to be consistent with them. PB is ideally suited for checking the validity of our method since, in addition to producing collinear parton densities, it also produces the corresponding transverse-dependent (TMD) ones, and these can then be directly compared to the transverse momentum distribution obtained from the parton shower. We show that TMD distributions which we in this way obtain from our modified <span>Pythia</span>8 shower using leading order (LO) parton densities and splitting functions are fully consistent with the corresponding leading order TMD densities. At next-to-leading order (NLO) it is not possible to achieve the same consistency using the built-in LO splitting functions in the shower, but we show that by introducing NLO splitting functions using a reweighting procedure, we can achieve consistency also at NLO. The method presented here, which we have named <span>Pdf2Isr</span>, can be easily extended to any collinear parton densities, as long as the exact conditions for the evolution are known. With the <span>Pdf2Isr</span> method we obtain an initial-state parton shower which in principle has no free parameters, and is fully consistent with collinear parton densities at LO and NLO.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 8","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14595-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832258","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":"Photo-response of the (N=Z) nucleus 28Si below 13.0 MeV","authors":"M. Scheck,&nbsp;R. Schwengner,&nbsp;O. Agar,&nbsp;R. Beyer,&nbsp;R. Chapman,&nbsp;K. Gladnishki,&nbsp;R.-D. Herzberg,&nbsp;H. Hoffmann,&nbsp;A. R. Junghans,&nbsp;D. Kocheva,&nbsp;S. E. Müller,&nbsp;D. O’Donnell,&nbsp;G. Rainovski,&nbsp;K. Römer,&nbsp;D. Savran,&nbsp;K. Schmidt,&nbsp;P. G. Thirolf,&nbsp;A. Wagner,&nbsp;O. Wieland,&nbsp;A. Yadav,&nbsp;F. Zhu","doi":"10.1140/epja/s10050-025-01647-w","DOIUrl":"10.1140/epja/s10050-025-01647-w","url":null,"abstract":"<div><p>The electric <i>E</i>1 and magnetic <i>M</i>1 dipole responses of the <span>(N=Z)</span> nucleus ²⁸Si were investigated in a nuclear resonance fluorescence experiment at the ELBE accelerator of the Helmholtz Zentrum Dresden-Rossendorf. The investigated energy range extends to 13.0 MeV, which corresponds to the kinetic energy of the electrons that were used to produce the unpolarised bremsstrahlung in the entrance channel of the ²⁸Si(<span>(gamma ,gamma ^{prime })</span>) reaction. The bremsstrahlung photons excited three <span>(J^{pi }=1^-)</span>, seven <span>(J^{pi }=1^+)</span>, and several <span>(J^{pi }=2^+)</span> states. De-excitation <span>(gamma )</span> rays were detected using the four high-purity germanium detectors of the <span>(gamma )</span>ELBE setup. The excellent background conditions allowed to identify nine previously unobserved <span>(gamma )</span>-ray transitions. In the investigated energy region of up to 13.0 MeV a total <span>(sum _i B(M1, 0^+ rightarrow 1^+_i)= 5.0(3)~mu _N^2)</span> strength is firmly observed with a possible addition of <span>(B(M1, 0^+ rightarrow 1^+_i) le 0.14~mu _N^2)</span> from levels for which the data allows to establish only an upper limit. Furthermore, below 13 MeV this <span>(N=Z)</span> nucleus exhibits a marginal isoscalar <i>E</i>1 strength of <span>(sum _i B(E1, 0^+ rightarrow 1^-)= 2.6(3) times 10^{-3})</span> <span>(hbox {e}^2 hbox {fm}^2)</span>, which exhausts only 0.026(2) % of the energy-weighted sum rule.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01647-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Dynamics of quantum droplets in a quasi-one-dimensional framework: an analytical approach","authors":"Akshat Pandey,&nbsp;Ayan Khan","doi":"10.1140/epjd/s10053-025-01046-2","DOIUrl":"10.1140/epjd/s10053-025-01046-2","url":null,"abstract":"<p>Quantum droplets have been recently observed in dipolar Bose–Einstein condensates (BECs) and in BEC mixtures. This forms the motivation for us to explore the dynamics of these droplets. We make use of the extended Gross–Pitaevskii equation which apart from the effective mean-field (MF) interaction also includes a <i>beyond</i> mean-field interaction. The competition of these two interactions in the context of droplet formation is explored. Further, the conditions for droplet formation are studied.\u0000</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814382","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":"Optical signatures of Einstein–Euler–Heisenberg AdS/dS black holes in the light of event horizon telescope","authors":"Khadije Jafarzade,&nbsp;Zeynab Bazyar,&nbsp;Sara Saghafi,&nbsp;Kourosh Nozari","doi":"10.1140/epjc/s10052-025-14521-2","DOIUrl":"10.1140/epjc/s10052-025-14521-2","url":null,"abstract":"<div><p>Recent observations of the supermassive black holes <span>( M87^{*} )</span> and Sgr <span>(hbox {A}^{*})</span> by the Event Horizon Telescope (EHT) have sparked intensified interest in studying the optical appearance of black holes (BHs). Inspired by this, we carry out a study on the optical features of Einstein–Euler–Heisenberg-Anti de Sitter/de Sitter (EEH-AdS/dS) BHs, including the trajectories of photons, shadow geometrical shape, energy emission rate, and deflection of light in this spacetime. Since, due to the nonlinear electrodynamics effects, photons propagate along null geodesics in an effective metric rather than the background metric, we first derive the effective metric of the EEH-AdS/dS BH. Then we study the null geodesics of the resulting effective metric and eventually compute the size of the EEH-AdS/dS BH shadow. To validate our results, we confront our results with the extracted information from EHT data of the supermassive BHs <span>( M87^{*} )</span> and estimate lower bounds for the shadow radius.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 8","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14521-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832214","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":"Thermal fluid flow modeling considering nonlinear thermal radiation and tetra-hybrid nanoliquid layer on Riga wedges: application in thermal engineering","authors":"Sadia Shakir,&nbsp;Saima Zainab,&nbsp;Noreen Sher Akbar,&nbsp;Kiran Batool,&nbsp;Taseer Muhammad","doi":"10.1140/epjp/s13360-025-06696-0","DOIUrl":"10.1140/epjp/s13360-025-06696-0","url":null,"abstract":"<div><p>This study presents a novel numerical investigation into the bioconvective stagnation point flow of tetra-hybrid nanofluids over a stretchable and shrinkable Riga wedge. The model uniquely integrates nonlinear thermal radiation, non-uniform heat sources, viscous dissipation, Soret and Dufour effects, magnetohydrodynamics (MHD), chemical reactions, and gyrotactic microorganisms in a porous medium—an innovative combination not previously addressed in the literature. The study visually analyzes flow dynamics, microorganism distribution, and heat and mass transfer. It also provides a numerical assessment of the skin friction coefficient, motile microorganism density number, and Sherwood and Nusselt numbers under varying parameter values. Both velocity and skin friction coefficient show similar trends concerning the wedge angle. The thermal transport rate and temperature exhibit consistent behavior with the non-uniform heat source parameter. An increase in the radiation parameter enhances thermal distribution, while a higher Dufour number leads to a rise in temperature. Similarly, a larger Soret number results in greater concentration levels. The microorganism field and motile density number respond inversely to the Peclet number, and the motile density number decreases with a reduction in the bioconvective Lewis number. It is observed that the results for the shrinking Riga wedge surface are more significant than those for the stretching case. Comparison with existing studies shows good agreement, validating the present approach and results. Applications of this research span drug delivery systems, microfluidic devices, microbial fuel cells, industrial cooling systems, and enhanced oil recovery.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814383","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}