物理最新文献

{"title":"Kinetic Alfvén solitary waves in multi-species magnetoplasma with Tsallis-distributed electrons and positrons","authors":"M. Sarker,&nbsp;M. M. Hasan,&nbsp;M. G. Shah,&nbsp;M. R. Hossen,&nbsp;A. A. Mamun","doi":"10.1140/epjd/s10053-025-01063-1","DOIUrl":"10.1140/epjd/s10053-025-01063-1","url":null,"abstract":"<p>The nonlinear dynamics of plasma waves in multi-species magnetized systems is of great importance for understanding energy transport and particle interactions in both astrophysical and laboratory environments. This study investigates heavy ion-acoustic kinetic Alfvén solitary waves (HIAKASWs) in a magnetized plasma composed of inertial thermal heavy ions and non-extensive electron–positron pairs. Using the reductive perturbation method, we derive both the Korteweg–de Vries (K-DV) and modified Korteweg–de Vries (MK-DV) equations, which capture the balance between dispersion and nonlinearity, and analyze their soliton solutions under different plasma conditions. The electron and positron populations are described by Tsallis non-extensive statistics, allowing exploration of deviations from Maxwellian behavior. The analysis reveals that the K-DV equation admits both compressive and rarefactive solitary structures, while the higher-order MK-DV formulation supports only compressive modes. Parametric investigations demonstrate that heavy ion thermal pressure and inertia play a dominant role in shaping wave amplitude and width compared to electron and positron effects. The results highlight the influence of non-extensivity, magnetic field strength, and propagation angle on solitary wave characteristics, with implications for plasma dynamics in astrophysical and laboratory environments.</p><p>The plots highlight the effects of <span>(beta )</span>, <span>(gamma )</span>, and heavy ion density on dispersion, nonlinearity, and electrostatic potential of K-DV and MK-DV solitons, relevant to astrophysical and laboratory plasmas.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145145402","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":"Quantum entanglement in cosmology","authors":"Alessio Belfiglio ,&nbsp;Orlando Luongo ,&nbsp;Stefano Mancini","doi":"10.1016/j.physrep.2025.09.001","DOIUrl":"10.1016/j.physrep.2025.09.001","url":null,"abstract":"<div><div>We discuss recent progress in the study of entanglement within cosmological frameworks, focusing on both momentum and position-space approaches and also reviewing the possibility to directly extract entanglement from quantum fields. Entanglement generation in expanding spacetimes can be traced back to the phenomenon of gravitational particle production, according to which the background gravitational field may transfer energy and momentum to quantum fields. The corresponding entanglement amount and its mode dependence are both sensitive to the field statistics and to the details of spacetime expansion, thus encoding information about the background. Gravitational production processes also play a key role in addressing the quantum-to-classical transition of cosmological perturbations. In order to directly extract entanglement from quantum fields, local interactions with additional quantum systems, working as detectors, have been suggested, leading to the formulation of the entanglement harvesting protocol. Despite harvesting procedures are currently unfeasible from an experimental point of view, various proposals for implementation exist and a proper modeling of detectors and local interactions is crucial to address entanglement extraction via realistic setups. In the final part of the work, we address entanglement characterization in position space, primarily focusing on black hole spacetimes. We first investigate a possible interpretation of Bekenstein–Hawking black hole entropy in terms of the entanglement entropy arising in discrete quantum field theories, on account of the area law. Then, we discuss the resolution of the black hole information paradox via the gravitational fine-grained entropy formula, which provides a new way to compute the entropy of Hawking radiation and allows to preserve unitarity in black hole evaporation processes.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1146 ","pages":"Pages 1-47"},"PeriodicalIF":29.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145134896","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":"Obliquely propagating nonlinear modes associated with ion-acoustic waves in a magnetized dissipative plasma with trapped electrons","authors":"S. Sultana,&nbsp;K. Habib,&nbsp;M. R. Hassan","doi":"10.1140/epjd/s10053-025-01067-x","DOIUrl":"10.1140/epjd/s10053-025-01067-x","url":null,"abstract":"<div><p>A three-component magnetized plasma consisting of inertial positive and negative ions, and non-inertial trapped electrons following the Schamel distribution function, is considered in the presence of wave dissipation factors: collisionality and fluid kinematic viscosity. A nonlinear modified Korteweg-de Vries-Burgers (mKdVB) equation is derived by employing the reductive perturbation approach, and the solitary and shock wave solutions are obtained via the tangent-hyperbolic (tanh) method. The influences of the nonlinear and dispersion coefficients via plasma parameters -the angle of obliqueness, the positive-to-negative ion number density, the negative-to-positive ion mass, the magnitude of the external magnetic field, and dissipation coefficients (arises due to the ion-neutral collision and ion fluid viscosity) on the formation and characteristics of the nonlinear obliquely propagating ion-acoustic solitary, solitonic-shock, and shock waves (monotonic and oscillatory) are theoretically and numerically analyzed. The numerical results might aid in a better understanding of how solitary and shock waves originate and propagate in plasmas with positive and negative ions in the presence of trapped particles.</p></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145145197","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":"Observational appearances of an inner extremal regular black hole illuminated by various accretion flows","authors":"Dan Zhang,&nbsp;Guoyang Fu,&nbsp;Xi-Jing Wang,&nbsp;Qiyuan Pan,&nbsp;Xiao-Mei Kuang,&nbsp;Jian-Pin Wu","doi":"10.1140/epjc/s10052-025-14782-x","DOIUrl":"10.1140/epjc/s10052-025-14782-x","url":null,"abstract":"<div><p>This paper investigates the observational appearances of an inner extremal regular black hole (IERBH) illuminated by various types of accretion models. The study reveals that when the BH is illuminated by specific accretion flows, the effects of quantum gravity become more pronounced, significantly impacting key observational features such as the shadow radius, photon ring, and total observed intensity. Specifically, the introduction of a more realistic radially infalling spherical accretion flow further accentuates these differences. This dynamic flow results in a darker central region in the BH image due to the Doppler effect, which modulates the observed intensity based on the relative motion of the infalling matter. The shadow radius and total observed intensity are notably affected by the quantum correction parameters, providing additional signatures that distinguish regular BHs from their classical counterparts.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14782-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110465","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":"High-precision shear parameters calculation method in lateral shearing interferometry via transfer learning-enhanced TransUNet","authors":"Bei Zhou,&nbsp;Ailing Tian,&nbsp;Liansheng Sui,&nbsp;Bingcai Liu,&nbsp;Hongjun Wang,&nbsp;Siqi Wang,&nbsp;Jiaming Su,&nbsp;Peifeng Liu","doi":"10.1007/s00340-025-08562-4","DOIUrl":"10.1007/s00340-025-08562-4","url":null,"abstract":"<div>\u0000 \u0000 <p>In lateral shearing interferometry, the discretely distributed edges and weak gradient variations in shearing interferograms can adversely affect the accurate calculation of shear parameters, consequently degrading wavefront reconstruction precision. To address this issue, this study proposes a TransUNet-based transfer learning method for shear parameter calculation. First the model pre-trained with simulated interferograms to learn fringe characteristics, then the model fine-tunes with limited real experimental data to overcome the scarcity of real interferograms. The model can achieve precise four-class segmentation of interferograms (background, two non-interference regions, and interference fringes), building upon the segmentation results, least-squares circle fitting algorithm is applied to simultaneously accomplish shear parameter calculation and wavefront center localization. Experimental validation demonstrates that the proposed method maintains excellent computational precision and automation levels even under noisy and weak-gradient conditions, while the shear parameters calculated by our method achieve significantly higher accuracy in wavefront reconstruction than existing mainstream algorithms.</p>\u0000 </div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 10","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110467","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 CERN n_TOF NEAR station for astrophysics- and application-related neutron activation measurements","authors":"The n_TOF Collaboration","doi":"10.1140/epja/s10050-025-01674-7","DOIUrl":"10.1140/epja/s10050-025-01674-7","url":null,"abstract":"<div><p>A new experimental area, the NEAR station, has recently been built at the CERN n_TOF facility, at a short distance from the spallation target (3 m). The new area, characterized by a neutron beam of very high flux, has been designed with the purpose of performing activation measurements of interest for astrophysics and various applications. The beam is transported from the spallation target to the NEAR station through a hole in the shielding wall of the target, inside which a collimator is inserted. The new area is complemented with a <span>(gamma )</span>-ray spectroscopy laboratory, the GEAR station, equipped with a high-efficiency HPGe detector, for the measurement of the activity resulting from irradiation of a sample in the NEAR station. The use of a moderator/filter assembly is envisaged, in order to produce a neutron beam with quasi-Maxwellian energy distribution, of different thermal energies, necessary for the determination of Maxwellian Averaged Cross Sections of astrophysical interest. A new fast-cycling activation technique is also being investigated for measurements of reactions leading to isotopes of very short half life.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01674-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110453","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":"Publisher Erratum: (b rightarrow c) semileptonic sum rule: extension to angular observables","authors":"Motoi Endo,&nbsp;Syuhei Iguro,&nbsp;Tim Kretz,&nbsp;Satoshi Mishima,&nbsp;Ryoutaro Watanabe","doi":"10.1140/epjc/s10052-025-14757-y","DOIUrl":"10.1140/epjc/s10052-025-14757-y","url":null,"abstract":"","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14757-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110466","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":"The optical analogy between a Lorentz-violating cosmos and a magneto-electric medium","authors":"Iman Motie,&nbsp;Brahim Lamine,&nbsp;Alain Blanchard,&nbsp;Rémy Battesti,&nbsp;Carlo Rizzo","doi":"10.1140/epjc/s10052-025-14755-0","DOIUrl":"10.1140/epjc/s10052-025-14755-0","url":null,"abstract":"<div><p>The goal of our study is to investigate the effects of Lorentz symmetry violation by examining the behavior of photons within the framework of the Standard Model Extension (SME). We show that, from an optical point of view, the Lorentz-violating cosmos is analogous to a magneto-electric medium like the quantum vacuum in the presence of the magnetic and electric field. This analogy provides a formulation for exploring experimental evidence of Lorentz symmetry violation in the propagation of light in a vacuum, in particular in the case of a radiation background observed like the CMB.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14755-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110456","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":"Nonlocal (N-alpha ) potential","authors":"M. I. Jaghoub,&nbsp;T. Aqel","doi":"10.1140/epja/s10050-025-01695-2","DOIUrl":"10.1140/epja/s10050-025-01695-2","url":null,"abstract":"<div><p>We used a nonlocal potential to account explicitly for nonlocalities in the <span>(N-alpha )</span> scattering process. By fitting elastic <span>(N-alpha )</span> angular distributions, over the energy range <span>(0.84 - 20.97)</span> MeV, we determined individual sets of nonlocal potential parameters and two global sets of fixed parameters one for <span>(n-alpha )</span> and the other for <span>(p-alpha )</span> elastic scattering. Our nonlocal potential model reproduced the elastic angular distributions for <span>(N-alpha )</span> and the total elastic cross section for <span>(n-alpha )</span> well. In addition, we calculated the nonlocal potential phase shifts corresponding to neutron and proton scattering off alpha particles. Our determined phase shifts are in good agreement with the experimental values. In addition, our nonlocal parameters reproduced the position of the <span>(P3/2^-)</span> resonance for the <span>(n-alpha )</span> and <span>(p-alpha )</span> scattering processes well. Accounting explicitly for nonlocalities in the <span>(N-alpha )</span> interactions can benefit studies that consider the <span>(t(d,N)alpha )</span> fusion reactions. The <span>(t(d,n)alpha )</span> reaction is important for its 17.6 MeV energy yield per fusion reaction, for its carbon-free energy production. The less prominent reaction that leads to bremsstrahlung <span>(gamma )</span> radiation is important as it provides real-time diagnostics regarding the fusion reaction rate.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110452","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":"Hamiltonian dynamics and extrinsic electric field indirect coupling as a tool for management of neuronal activity in a generalized two dimensional Hindmarsh–Rose model","authors":"N. S. Mundih,&nbsp;A. Mvogo,&nbsp;D. Belobo Belobo,&nbsp;C. B. Tabi,&nbsp;T. C. Kofané","doi":"10.1140/epjb/s10051-025-01044-8","DOIUrl":"10.1140/epjb/s10051-025-01044-8","url":null,"abstract":"<p>In this work, we investigate a generalized two dimensional Hindmarsh−Rose neuronal model which single out the distinct roles of the Hamiltonian and its time-derivative (instantaneous power) in shaping the neuronal activity of neurons coupled indirectly by an extrinsic electric field adjustable by an experimenter. By imposing a periodic extrinsic field, we demonstrate how neurons are driven into complete synchronization by the extrinsic electric field and we identify critical thresholds values of the amplitude and the frequency of the extrinsic electric field below which neuronal activity with amplitude death occurs. Strikingly, exceeding these thresholds values triggers a rebound of oscillatory activity. Analytical calculations using the Helmholtz’s theorem yield closed−form expressions for the Hamiltonian along with its instantaneous power reveal that the contributions of the extrinsic electric field add up in each neuron. Intensive numerical simulations confirm the existence of sharp amplitude and frequency boundaries separating regimes of neuronal silencing and revival of neuronal dynamics. Moreover, variations in neuronal radius are shown to modulate excitability through capacitance effects, with larger cells exhibiting suppressed oscillations. Our results highlight crucial mechanisms by which modulated extrinsic electric fields regulate neuronal behavior offering potential control strategies for neuromodulation applications.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 9","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110491","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}