物理最新文献

{"title":"Radiative properties and QPOs around charged black hole in Kalb–Ramond gravity","authors":"Shokhzod Jumaniyozov,&nbsp;Muhammad Zahid,&nbsp;Mirzabek Alloqulov,&nbsp;Inomjon Ibragimov,&nbsp;Javlon Rayimbaev,&nbsp;Sardor Murodov","doi":"10.1140/epjc/s10052-025-13863-1","DOIUrl":"10.1140/epjc/s10052-025-13863-1","url":null,"abstract":"<div><p>Studies of accretion disc luminosities and quasiperiodic oscillations around black holes may help us understand the gravitational properties of black hole spacetime. This work is devoted to studying the radiation properties of the accretion disk around the black holes in Kalb–Ramond gravity. We investigate the event horizon of the black hole spacetime and calculate the effective gravitational mass of the spacetime. Also, we analyze the circular motion of test particles in the black hole spacetime. The effects of the black hole charge and KR parameters on the particles’ effective mass, energy, and angular momentum at circular orbits and innermost stable circular orbits are studied. The frequency of Keplerian orbits and the radial and vertical oscillations of the particles along stable orbits are calculated and applied to analyze the existence of QPO in relativistic precession, warped disc, and epicyclic resonance models. QPO orbits’ locations with ratios of upper and lower frequencies of twin-peaked QPOs 3:2, 4:3, and 5:4 are analyzed compared to ISCO. We also obtain constrain values for the black hole mass, charge, KR field parameter, and QPO orbits found using Markovian chain Monte Carlo (MCMC) simulations for stellar mass (XTE J1550, GRS 1915+105), intermediate mass (M82-X1), and supermassive black holes (Sgr A*). Finally, we explore the radiative properties of the accretion disk around the charged black hole in KR gravity, such as the total radiation flux, accretion disc temperature, and differential luminosity.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13863-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108277","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":"Generation of anomalously scattered lump waves for (2+1)-dimensional Date–Jimbo–Kashiwara–Miwa equation","authors":"Tianwei Qiu,&nbsp;Zhen Wang,&nbsp;Xiangyu Yang","doi":"10.1140/epjp/s13360-025-06047-z","DOIUrl":"10.1140/epjp/s13360-025-06047-z","url":null,"abstract":"<div><p>The anomalous scattering of lump waves governed by the Date–Jimbo–Kashiwara–Miwa (DJKM) equation is explored via two distinct methods. The second-order anomalously scattered lump is derived by degenerating the M-lump solution under the limit of infinite phase. Higher order anomalously scattered lumps are obtained through the degeneration of lump chains described by infinite periods, with analyses of two types of degenerate lump chains. A thorough asymptotic analysis is employed to investigate both the dynamic behavior and scattering angles of the anomalous scattering phnomena. Notably, the triangular structures of higher order lumps are found to be closely related to the Yablonskii-Vorob’ev polynomials. These insights may deepen our understanding of the intrinsic characteristics of lump waves.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107849","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 utilization of magneto-hydrodynamics framework in expansion of magnetized viscous conformal flow","authors":"M. Karimabadi,&nbsp;A. F. Kord,&nbsp;B. Azadegan","doi":"10.1140/epja/s10050-025-01486-9","DOIUrl":"10.1140/epja/s10050-025-01486-9","url":null,"abstract":"<div><p>This study focuses on the evolution of magnetized quark–gluon plasma (QGP) within the framework of magneto-hydrodynamics (MHD). We investigate the temporal and spatial dynamics of QGP with additional second-order viscous corrections, considering the effects of a magnetic field generated during the early stages of relativistic heavy-ion collisions. In our analysis, we assume boost invariance along the beamline, represented by the <span>(z)</span>-coordinate, and fluid expansion along the <span>(x)</span>-direction. The magnetic field is assumed to be oriented perpendicular to the reaction plane, aligning with the <span>(y)</span>-direction. Additionally, we consider the fluid to have infinite electrical conductivity, simplifying the treatment of electromagnetic effects. To characterize the system, we solve the coupled Maxwell’s equations and the conservation equations of relativistic hydrodynamics. This approach allows us to elucidate the time and space dependence of key physical quantities, including the energy density, fluid velocity, and magnetic field within the transverse plane of the viscous, magnetized plasma. By deriving these quantities, we also compute the hadron spectra and perform a comparative analysis with experimental data to validate our theoretical predictions.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108278","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":"Synthesis and photocatalytic performance of ZnS/rGO nanocomposites for methylene blue degradation","authors":"Tofik Achalu Hussen,&nbsp;Mulualem Abebe Mekonnen,&nbsp;Newayemedhin A. Tegegne,&nbsp;Dinsefa Mensur Andoshe,&nbsp;Fekadu Gashaw Hone","doi":"10.1007/s00339-025-08277-5","DOIUrl":"10.1007/s00339-025-08277-5","url":null,"abstract":"<div><p>This study focused on enhancing the photocatalytic performance of Zinc Sulfide through reduced graphene oxide by forming (ZnS/rGO) nanocomposites. Various characterization techniques included X-ray diffraction (XRD), FTIR, SEM–EDX, UV–Vis diffuse reflection spectra (DRS), thermogravimetric analysis (TGA), and photoluminescence spectroscopy (PL) were used to study various properties of the prepared nanocomposites. Successful synthesis and uniform distribution of ZnS nanoparticles on rGO sheet were confirmed through SEM, and dye degradation monitored by UV–Vis spectroscopy. Increasing rGO content improved crystallinity, as indicated by sharper XRD diffraction peaks around 27 , indexed to the (100) plane. The PL spectra further indicated that the enhancement in electron–hole generation within the nanocomposite was observed as the rGO content increased from 4wt% to 12wt%. The optical band gaps were determined to be 3.51 eV for ZnS and 3.68 eV for ZnS/rGO. The photocatalysis experiments were performed by adding 0.04 g of either pure ZnS or ZnS/rGO nanocomposite to 80 ml of an aqueous solution containing Methylene Blue dye at a concentration of 15 mg per liter (15 ppm), with a pH of 12 under 300 w hydrogen lamp. The presence of rGO enhanced charge separation, resulting in increased photocatalytic activity, with ZnS/rGO-12wt % achieving 96.99% degradation after 90 min of light exposure. The photocatalyst showed good stability, with a degradation efficiency of 92.6% in the first cycle, dropping to 86.8% in the second. All the results are revealed that, ZnS/rGO nanocomposites show significant potential for degrading methylene blue (MB) pollutants under visible light.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross-diffusion-induced instabilities in a cooperative hunting population with Allee effect","authors":"Gourav Mandal,&nbsp;Lakshmi Narayan Guin,&nbsp;Santabrata Chakravarty","doi":"10.1140/epjp/s13360-025-06017-5","DOIUrl":"10.1140/epjp/s13360-025-06017-5","url":null,"abstract":"<div><p>The spatiotemporal complexity of a system of interacting species, influenced by hunting cooperation and the additive Allee effect, has garnered significant attention within the ecological framework. This study investigates whether interactions among species can stabilize the dynamics of environmental communities and promote coexistence, employing a cross-diffusion-driven species interaction model. The local and global bifurcation behaviour of the proposed system and the stability of all potential equilibrium points in the absence of diffusion have been comprehensively examined. Numerical simulations have been conducted to validate the analytical findings and assess the applicability of the cross-diffusive model. In a two-dimensional plane, the evolution of diffusion-driven pattern generation, known as black-eye replication, around the coexistence equilibrium point has been presented. Furthermore, it has been demonstrated that species interactions within the context of cross-diffusion can exacerbate the instability dynamics of ecological populations by generating spatial patterns. The results underscore the crucial role of cross-diffusion-driven instability in maintaining ecosystem diversity and structure.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107852","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":"Coherent generation of superluminal and subluminal propagation of structured light in five level atomic medium","authors":"Zareen A. Khan,&nbsp;Abdul Majeed,&nbsp;Imdad Ullah,&nbsp;Amir Ali","doi":"10.1007/s00340-025-08394-2","DOIUrl":"10.1007/s00340-025-08394-2","url":null,"abstract":"<div><p>Here, we investigate the structured superluminal and subluminal light propagation in the medium generated through a five-level atomic configuration controlled by a tiny probe and multiple of the control field. The absorption and dispersion are altered with the topological charges of control fields. The maxima and minima of absorption and corresponding normal/anomalous dispersion region are enhanced according to the <span>(2ell)</span> condition in the medium. The group index differs in the domain of <span>(-15000le n_g le 17500)</span> in the position ranges of <span>(-1mu mle x,y le 1 mu m)</span>. The corresponding velocity of the envelope wave <span>(v_{g})</span> is calculated by <span>(c/n_g)</span>. The subluminal and superluminal maximum and minimum regions are also enhanced with the <span>(2ell)</span> condition in the medium. The modified work of this manuscript is useful for storage devices, imaging coding, and designing technology.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 2","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107934","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":"Analysis and compensation of alignment error in laser scanning heat-mode lithography system","authors":"Xiaozhong Xu,&nbsp;Zhihong Huang,&nbsp;Tianyu Gao,&nbsp;Jingsong Wei","doi":"10.1007/s00340-025-08393-3","DOIUrl":"10.1007/s00340-025-08393-3","url":null,"abstract":"<div><p>Alignment error significantly influences the fabrication quality of micro/nano structures in laser scanning heat-mode lithography systems. This paper presents an effective compensation strategy to address this issue. A laser heat-mode lithography system is established with a tightly focused objective lens and a grid scanning strategy, achieving a minimum grid size of 6 nm. The factors affecting alignment accuracy are then analyzed from the perspectives of the positioning error, galvanometer scanning distortion and coordinate system inclination. Following this, a compensation strategy is proposed, which adjusts the coordinate system of the dual-galvanometer to compensate alignment error. Experiments demonstrate the effectiveness, significantly reducing the maximum alignment error from 92.4 nm to 8.4 nm, improving alignment accuracy by approximately 91%. Furthermore, the fabrication of various structures with a minimum linewidth of 150 nm further confirms the excellent alignment performance of the system and demonstrates the advantages of laser heat-mode lithography. This work provides flexible compensation strategies for improving alignment accuracy in the dual-galvanometer laser scanning lithography system, paving the way for advancements in systems based on direct laser writing or other step-stitching lithography techniques.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 2","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107848","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 stability of anisotropic compact stars influenced by dark matter under teleparallel gravity: an extended gravitational deformation approach","authors":"Sneha Pradhan,&nbsp;Piyali Bhar,&nbsp;Sanjay Mandal,&nbsp;P. K. Sahoo,&nbsp;Kazuharu Bamba","doi":"10.1140/epjc/s10052-025-13849-z","DOIUrl":"10.1140/epjc/s10052-025-13849-z","url":null,"abstract":"<div><p>In our investigation, we pioneer the development of geometrically deformed strange stars within the framework of teleparallel gravity theory through gravitational decoupling via the complete geometric deformation (CGD) technique. The significant finding is the precise solution for deformed strange star (SS) models achieved through the vanishing complexity factor scenario. Further, we introduce the concept of space-time deformation caused by dark matter (DM) content in DM haloes, leading to perturbations in the metric potentials <span>(g_{tt})</span> and <span>(g_{rr})</span> components. Mathematically, this DM-induced deformation is achieved through the CGD method, where the decoupling parameter <span>(alpha )</span> governs the extent of DM influence. To validate our findings, we compare our model predictions with observational constraints, including GW190814 (with a mass range of <span>(2.5-2.67 M_{odot })</span>) and neutron stars (NSTRs) such as EXO 1785-248 [mass=<span>(1.3_{-0.2}^{+0.2}~M_{odot })</span>], 4U 1608-52 [mass=<span>(1.74_{-0.14}^{+0.14}~M_{odot })</span>], and PSR J0952-0607 [mass=<span>(2.35_{-0.17}^{+0.17}~M_{odot })</span>]. Our investigation delves into the stability of the model by considering causality conditions, Herrera’s cracking method, the adiabatic index, and the Harrison–Zeldovich–Novikov criterion. We demonstrate that the developed model mimics a wide range of recently observed pulsars. To emphasize its compatibility, we highlight the predicted mass and radius in tabular form by varying both the parameters <span>(alpha )</span> and <span>(zeta _1)</span>. Notably, our findings are consistent with the observation of gravitational waves from the first binary merger event. Furthermore, we compare our results with those obtained for a slow-rotating configuration. In addition to this, we discuss the moment of inertia using the Bejger–Haensel approach in this formulation.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13849-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108276","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":"Theoretical study of the open-flavored tetraquark (T_{cbar{s}}(2900)) in the process (Lambda _brightarrow K^0D^0Lambda )","authors":"Wen-Tao Lyu,&nbsp;Yun-He Lyu,&nbsp;Man-Yu Duan,&nbsp;Guan-Ying Wang,&nbsp;Dian-Yong Chen,&nbsp;En Wang","doi":"10.1140/epjc/s10052-025-13805-x","DOIUrl":"10.1140/epjc/s10052-025-13805-x","url":null,"abstract":"<div><p>Recently, the LHCb Collaboration has measured the processes <span>(B^+rightarrow D^-D_s^+pi ^+)</span> and <span>(B^+rightarrow bar{D}^0D_s^+pi ^+)</span>, where the <span>(D_s^+pi ^-)</span> and <span>(D_s^+pi ^+)</span> invariant mass distributions show the significant signals of two new open-flavored tetraquark states <span>(T_{cbar{s}}(2900)^0)</span> and <span>(T_{cbar{s}}(2900)^{++})</span>, as the two of the isospin triplet. In this work, we have investigated the process <span>(Lambda _brightarrow K^0D^0Lambda )</span> by taking into account the tetraquark state <span>(T_{cbar{s}}(2900)^0)</span> and the intermediate nucleon resonance <span>(N^*(1535))</span>, which could be dynamically generated by the interactions of the <span>(D^*K^*/D^*_srho )</span> and the pseudoscalar meson-octet baryon, respectively. Our results show that a clear peak of the open-flavored tetraquark <span>(T_{cbar{s}}(2900))</span> may appear in the <span>(K^0D^0)</span> invariant mass distribution of the process <span>(Lambda _brightarrow K^0D^0Lambda )</span>, which could be tested by future experiments.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13805-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107995","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":"Theoretical study of magnetic, magnetocaloric, and hysteresis behavior of the antiperovskite compound Mn3AlN","authors":"M. Salama,&nbsp;E. M. Jalal,&nbsp;H. Saadi,&nbsp;H. Kerrai,&nbsp;N. Hachem,&nbsp;E. B. Choubabi,&nbsp;M. El Bouziani","doi":"10.1007/s00339-025-08291-7","DOIUrl":"10.1007/s00339-025-08291-7","url":null,"abstract":"<div><p>In this study, we explore the magnetic, magnetocaloric properties, as well as the hysteresis behavior of the antiperovskite compound Mn₃AlN using a theoretical approach based on the mean-field approximation. We examine the effects of the magnetic field and exchange interaction on the magnetization, magnetic susceptibility, magnetic entropy change, as well as the hysteresis behavior of this material. The results show that Mn₃AlN undergoes a second-order magnetic phase transition, with a maximum magnetocaloric effect around the critical temperature. Moreover, the relative cooling power RCP increases monotonically with magnetic field strength, suggesting that this compound could be promising for magnetic refrigeration applications. The maximum values of the magnetic entropy change <span>(Delta S_{m})</span> and the relative cooling power RCP are 0.21 and 5.14, respectively, under an applied magnetic field of <span>(h=2.5)</span>. Hysteresis behavior is also studied, revealing a decrease in coercivity and remanent magnetization with increasing temperature, until the hysteresis loop completely disappears above the critical temperature.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}