物理最新文献

{"title":"Restricted phase space thermodynamics of 4D dyonic AdS black holes: insights from Kaniadakis statistics and emergence of superfluid (lambda )-phase transition","authors":"Abhishek Baruah,&nbsp;Prabwal Phukon","doi":"10.1140/epjc/s10052-025-14212-y","DOIUrl":"10.1140/epjc/s10052-025-14212-y","url":null,"abstract":"<div><p>We study the thermodynamics of 4<i>D</i> dyonic AdS black hole in the Kaniadakis statistics framework using the Restricted Phase Space (RPST) formalism. This framework provides a non-extensive extension of classical statistical mechanics, drawing inspiration from relativistic symmetries and presenting a fresh perspective on black hole thermodynamics. Our study analyzes how including Kaniadakis entropy modifies the phase transition of the dyonic black holes. We consider the central charge <i>C</i> and its conjugate chemical potential <span>(mu )</span> as the thermodynamic variable along with others except the pressure and volume. Due to the addition of the magnetic charge <span>(tilde{Q}_m)</span>, the study of the phase transition becomes much richer by obtaining a non-equilibrium phase transition from an unstable small black hole to a stable large black hole along with the Van der Waals and superfluid phase transition with an extra unstable branch in the <span>(T-S)</span> processes. In the <span>(F-T)</span> plot, we get an extra Davies type with an extra branch phase transition. Including the deformation parameter <span>(kappa )</span> introduces an unstable (ultra-large BH) branch seen in almost all the plots. Turning off the magnetic charge flips the direction of the phase transition seen during its presence. Also, in the plots varying <span>(kappa )</span> match with the plot varying <i>C</i> which underlines some sort of correspondence in its meaning which is not possible to observe in Gibbs–Boltzmann statistics. As the entropy models change the homogeneity is not lost where mass is of the first order and the rest is zeroth order. The <span>(mu -C)</span> processes in quite similar across black hole systems and entropy formulation marking some kind of universality of this process. Our study shows that modified entropy, unlike in certain alternative gravity models, does not give rise to a new thermodynamic universality class but retains consistency with standard Einstein–Hilbert black hole behavior.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14212-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949519","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":"Dynamic oscillatory radiation pressure on a perfect electromagnetic conductor (PEMC) circular cylinder","authors":"Yuchen Zang","doi":"10.1140/epjp/s13360-025-06318-9","DOIUrl":"10.1140/epjp/s13360-025-06318-9","url":null,"abstract":"<div><p>The electromagnetic radiation pressure is characterized by an oscillatory behavior when the targeted object is illuminated by an amplitude-modulated wave whose wave intensity changes over time. In this study, a theoretical formalism is developed to investigate the dynamic radiation pressure acting on a perfect electromagnetic conductor (PEMC) cylinder as a typical material exhibiting rotary polarization. The incident field is assumed to be a transverse magnetic (TM) plane wave driven at two slightly different frequencies. Using the modal expansion method in cylindrical coordinates as well as the short-term time average of the Maxwell’s stress tensor over the surface of the cylinder, the exact series expansions for the dimensionless dynamic radiation pressure function are obtained, which represents the radiation pressure acting on the cylinder per unit cross-sectional area and per unit wave energy density. Numerical computations are also performed with particular emphasis on the cross-term factor generated by the interference phenomenon of two primary waves at the beating frequency. The simulated results demonstrate that there is a slight decrease for the co-polarized component of the radiation pressure while a minor increase for the cross-polarized component with growing difference frequencies. Moreover, a significant modification caused by the mode conversion effect must be taken into account when the cylinder has an admittance close to one. Potential applications can be sought in non-contact particle manipulation using the dynamic oscillatory radiation pressure induced by amplitude-modulated electromagnetic waves.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944275","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":"Impacts of perfect fluid dark matter on spacetime geometry: the exponential metric","authors":"Jan Kuncewicz","doi":"10.1140/epjc/s10052-025-14276-w","DOIUrl":"10.1140/epjc/s10052-025-14276-w","url":null,"abstract":"<div><p>Astrophysical observations provide compelling evidence for the existence of dark matter, a non-luminous component dominating the universe’s mass-energy budget. Its gravitational influence is well-established on galactic scales; however, dark matter’s precise nature and effect on spacetime geometry remain open questions. This study investigates modifications to the Schwarzschild metric due to the presence of dark matter, modeled as a perfect fluid with a specific equation of state. We derive an “exponential” metric incorporating this dark matter contribution and calculate its key characteristics: the event horizon, innermost stable circular orbit (ISCO), and photon sphere. Comparing these with Schwarzschild predictions reveals distinct deviations dependent on the dark matter distribution. Furthermore, we analyze the orbital velocity profiles derived from the exponential metric, demonstrating its potential to explain the observed flat rotation curves of galaxies. Our results underscore the importance of considering modified metrics in accurately describing spacetime near massive objects and provide a theoretical framework for further investigations into dark matter’s role in galactic dynamics.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14276-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944277","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":"Discovery prospects for the light charged Higgs boson decay to an off-shell top quark and a bottom quark at future high-energy colliders","authors":"Jinheung Kim,&nbsp;Soojin Lee,&nbsp;Prasenjit Sanyal,&nbsp;Jeonghyeon Song,&nbsp;Daohan Wang","doi":"10.1140/epjc/s10052-025-14244-4","DOIUrl":"10.1140/epjc/s10052-025-14244-4","url":null,"abstract":"<div><p>The charged Higgs boson (<span>(H^pm )</span>) with a mass below the top quark mass remains a viable possibility within the Type-I two-Higgs-doublet model under current constraints. While previous LHC searches have primarily focused on the <span>(H^pm rightarrow tau ^pm nu )</span> decay mode, the decay channel into an off-shell top quark and a bottom quark, <span>(H^pm rightarrow t^*b)</span>, is leading or subleading for <span>(H^pm )</span> masses between 130 and 170 GeV. This study investigates the discovery potential of future colliders for this off-shell decay mode through pair-produced charged Higgs bosons decaying via <span>(H^+H^-rightarrow t^*btau nu rightarrow bbjjtau nu )</span>. We perform signal-to-background analyses at the HL-LHC and a prospective 100 TeV proton–proton collider, employing cut-flow strategies and the Boosted Decision Tree method. However, due to the softness of the <i>b</i> jets, signal significances fall below detection thresholds at these facilities. Extending our study to a multi-TeV muon collider (MuC), we demonstrate that a 3 TeV MuC achieves high signal significance, surpassing the <span>(5sigma )</span> threshold with an integrated luminosity of 1 ab<span>(^{-1})</span> and a 10% background uncertainty. Specifically, for <span>(M_{H^pm } = 130)</span>, 150, and 170 GeV, the significances are 13.7, 13.5, and 6.06, respectively. In contrast, a 10 TeV MuC requires 10 ab<span>(^{-1})</span> to achieve similar results. Our findings highlight the critical role of the MuC in probing the new signal channel <span>(H^pm rightarrow t^*b)</span>, offering a promising avenue for future charged Higgs boson searches involving off-shell top quarks.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14244-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944278","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":"Constraining primordial non-Gaussianity by combining photometric galaxy and 21 cm intensity mapping surveys","authors":"Mponeng Kopana,&nbsp;Sheean Jolicoeur,&nbsp;Roy Maartens","doi":"10.1140/epjc/s10052-025-14241-7","DOIUrl":"10.1140/epjc/s10052-025-14241-7","url":null,"abstract":"<div><p>The fluctuations produced during cosmic inflation may exhibit non-Gaussian characteristics that are imprinted in the large-scale structure of the Universe. This non-Gaussian imprint is an ultra-large scale signal that can be detected using the power spectrum. We focus on the local-type non-Gaussianity <span>(f_textrm{NL})</span> and employ a multi-tracer analysis that combines different probes in order to mitigate cosmic variance and maximize the non-Gaussian signal. In our previous paper, we showed that combining spectroscopic galaxy surveys with 21 cm intensity mapping surveys in interferometer mode could lead to a <span>(sim )</span> 20–30% improvement in the precision on this non-Gaussian signal. Here we combine the same 21 cm experiments, including also single-dish surveys, with photometric galaxy surveys. The 21 cm single-dish surveys are based on MeerKAT and SKAO and the interferometric surveys are alike to HIRAX and PUMA. We implement foreground-avoidance filters and utilize models for the 21 cm thermal noise associated with single-dish and interferometer modes. The photometric galaxy surveys are similar to the DES and LSST. Our multi-tracer Fisher forecasts show a better precision for the combination of the photometric galaxy surveys and 21 cm interferometric surveys than with the 21 cm single-dish surveys – leading to at most an improvement of <span>(23%)</span> in the former case and <span>(16%)</span> in the latter case. Furthermore, we examine the impact of varying the foreground filter parameter, redshift range and sky area on the derived constraint. We find that the <span>(f_textrm{NL})</span> constraint is highly sensitive to both the redshift range and sky area. The foreground filter parameter shows negligible effect.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14241-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949586","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":"Weakly nonlinear analyses on double-diffusive convection of Casson fluid in a porous medium with an internal heat and gravity modulation","authors":"L. Venkat Reddy,&nbsp;Ravi Ragoju,&nbsp;Suman Shekhar,&nbsp;Dhananjay Yadav","doi":"10.1140/epjb/s10051-025-00947-w","DOIUrl":"10.1140/epjb/s10051-025-00947-w","url":null,"abstract":"<p>The influence of internal heat and gravity modulation on the onset of double-diffusive convection of Casson fluid using weakly nonlinear analysis is examined. Porous material generates its self heat under different types of situations. Casson fluids have found widespread use in food industries. Chocolate production, for instance, relies on controlling rheological behavior, influenced by ingredients and processing techniques. Casson fluid model is also applied in medical research to mimic human blood rheology. Non-newtonian fluid and their viscosity changes with applied stresses. These fluids demonstrate complex flow behavior in food processing. But so far, the influence of internal heat and gravity modulation on casson fluid is not discussed. Power series expansion method is used where disturbances are expressed as power series. Ginzburg–Landau amplitude equation was derived to quantify heat transfer and mass transport using Nusselt and Sherwood number, respectively. Our investigation revealed that increasing values of Darcy number, Casson parameter, and solutal Rayleigh number enhances the Nusselt number and Sherwood number, indicating improved heat and mass transfer. Furthermore, decreasing Nusselt number and Sherwood number by increasing the modulation frequency produces less heat and mass transport. Conversely, increasing the modulation amplitude increases the Nusselt number and Sherwood number.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949561","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 characterization of defect chalcopyrite ZnIn2Te4 thin films for opto-electronic device implementations","authors":"E. G. El-Metwally,&nbsp;A. M. Shakra,&nbsp;Dalia M. Abdel-Basset","doi":"10.1140/epjb/s10051-025-00940-3","DOIUrl":"10.1140/epjb/s10051-025-00940-3","url":null,"abstract":"<div><p>Defect chalcopyrite compounds have emerged as promising materials for optoelectronic applications. In this study, we investigate the linear and nonlinear optical properties of ZnIn₂Te₄ thin films deposited with varying thicknesses (113–385 nm). The transmittance and reflectance measurements were performed across a wide spectral range (400–2500 nm), revealing two distinct optical band gaps of 0.932 eV (indirect) and 1.36 eV (direct). The refractive index <span>(n)</span> and extinction coefficient <span>(k)</span> exhibited normal dispersion behavior. While the skin depth decreased and optical conductivity increased with photon energy. Using the Wemple–DiDomenico single oscillator model, we extracted key optical parameters such as the oscillator energy <span>({E}_{o})</span>, dispersion energy <span>({E}_{d})</span>, infinite dielectric constant <span>({varepsilon }_{infty })</span>, and oscillator strength <span>({S}_{o})</span>. Energy loss functions (<span>(text{VELF})</span> and <span>(text{SELF})</span>) also increased with photon energy. Nonlinear optical properties, including the linear susceptibility <span>({chi }^{(1)})</span>, third-order susceptibility <span>({chi }^{(3)})</span>, and nonlinear refractive index <span>({n}_{2})</span>, were evaluated, yielding values of 0.944, 1.35 × 10⁻¹⁰ <span>(esu)</span>, and 1.42 × 10⁻⁹ <span>(esu)</span>, respectively. These results demonstrate the potential of ZnIn₂Te₄ for use in optical devices such as filters, photodetectors, and nonlinear switches.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944279","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":"Investigation of the impact of Ti doping on graphene in the structural resistance of copper-graphene nanolayer composites using molecular dynamics (MD) simulations","authors":"F. Mirzaei Mohammadabadi,&nbsp;Behnam Azadegan,&nbsp;J. Baedi,&nbsp;E. Koushki,&nbsp;M. Amini","doi":"10.1007/s00339-025-08547-2","DOIUrl":"10.1007/s00339-025-08547-2","url":null,"abstract":"<div><p>In environments exposed to high neutron radiation, understanding the relationship between structural stability and the number of defects is essential. This knowledge aids in designing materials with high radiation tolerance and in predicting their behavior under various irradiation conditions. In this study, the radiation resistance and interface stability of a Ti-doped copper–graphene nanolayer composite are examined using atomistic simulations. The graphene layer within the copper–graphene nanocomposite is doped with Ti atoms at concentrations of 0.005, 0.01, 0.02, 0.03, 0.035, and 0.04 wt%. Simulations are conducted for primary knock-on atoms (PKA) with energies of 3, 6, and 9 keV. The study focuses on factors such as the number of surviving point defects as a function of the PKA distance from the graphene layer, the evolution of kinetic and total energy of atoms, and the number of point defects (vacancies and interstitials) versus different Ti concentrations. The findings reveal that Ti doping significantly reduces the number of defects up to a specific concentration, thereby improving the structural stability of the nanocomposite.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944369","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":"Black hole thermodynamics via Tsallis statistical mechanics","authors":"Phuwadon Chunaksorn,&nbsp;Ratchaphat Nakarachinda,&nbsp;Pitayuth Wongjun","doi":"10.1140/epjc/s10052-025-14239-1","DOIUrl":"10.1140/epjc/s10052-025-14239-1","url":null,"abstract":"<div><p>An investigation of black hole thermodynamics based on Tsallis statistical mechanics is explored through the study of the thermodynamics of a gas system located near the horizon of a black hole. In spite of the difficulty in exploring black hole thermodynamics through statistical mechanics, the entropy of the nearby gas system is found to be proportional to the black hole’s horizon area using Gibbs–Boltzmann statistical mechanics. This allows us to study black hole thermodynamics by using statistical mechanics through the thermodynamic behaviors of the gas system. Since the entropy of the black hole is proportional to the horizon area, it is more suitable to use non-extensive statistical mechanics instead of the usual Gibbs–Boltzmann ones. In this work, the black hole entropy is derived based on Tsallis statistical mechanics, one of well-known non-extensive statistical mechanics. It is found that the black hole entropy gets a modification due to non-extensivity. By using such an entropy, the black hole can be stabilized due to the non-extensivity, and the bound on the non-extensive parameter is also determined. \u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14239-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944244","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":"Heavy quarkonia suppression at (sqrt{s_{NN}}=5.02 ~TeV) using kinetic approach","authors":"Mayank K. Mishra,&nbsp;B. K. Pandey,&nbsp;P. K. Srivastava","doi":"10.1140/epjp/s13360-025-06338-5","DOIUrl":"10.1140/epjp/s13360-025-06338-5","url":null,"abstract":"<div><p>Production and suppression of heavy quarkonium states are one of the most studied topics in heavy ion collision field. Recently, the experimental data regarding quarkonia suppression have been obtained and analysed by CMS and ALICE collaboration at <span>(sqrt{s_{NN}}=5.02)</span> TeV. In this article, we would like to provide the physical interpretation to these data by using our recently proposed kinetic model for quarkonia suppression. In the recent past, our kinetic model provides satisfactory results for quarkonia suppression at <span>(sqrt{s_{NN}}=200)</span> GeV and 2.76 TeV from STAR collaboration at RHIC and from CMS collaboration at LHC, respectively. These results suggest that the effect of regeneration becomes quite important at LHC energies. In the present work, we have improved our model by incorporating another physical process which regenerates the singlet quarkonia states in addition to the regeneration by radiating a soft gluon. We proceed with our improved model calculations to obtain the variation of nuclear modification factor for different quarkonia states with respect to centrality at <span>(sqrt{s_{NN}}=5.02)</span> TeV. Further, we have calculated the nuclear modification of charmonia states with respect to bottomonia states. This work will help in putting a stringent constraint on our model parameters.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949520","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}