High Energy Density Physics最新文献

{"title":"Exploring hybrid scalar factor and ekpyrotic bouncing cosmology in f(Q,R) Gravity","authors":"Aimen Rauf ,&nbsp;Bander Almutairi ,&nbsp;A.S. Khan","doi":"10.1016/j.hedp.2025.101188","DOIUrl":"10.1016/j.hedp.2025.101188","url":null,"abstract":"<div><div>In this study, we delve into the evolution of the Hubble parameter, focusing on its sign reversal in the early universe and its stability within <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity. Methods are employed to investigate the universe’s behavior concerning hybrid scale factor scenarios, including the sub-relativistic, radiation, ultra-relativistic, dust, and stiff fluid universes, concerning the equation of state (EoS) parameters. This research builds on previous ones by providing a more in-depth investigation of the bouncing scenarios inside the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity framework, reconstructing gravitational Lagrangians established for certain parameter values. Once rebuilt, these Lagrangians allow the examination of energy conditions required for a realistic bouncing model and give analytical answers to the ekpyrotic (Ekkart) bounce model. The function of exotic matter, renowned for its high negative pressure, is the key factor promoting the universe’s acceleration expansion. An analysis of <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity theories, particularly focusing on bouncing scenarios, distinguishes this work from earlier studies on alternative gravity theories and their cosmological implications. This research offers a detailed investigation of bouncing models along with a detailed examination of the energy conditions present in <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101188"},"PeriodicalIF":1.6,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738599","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 screening effect of the plasma ions on the electron-impact excitation process and subsequent polarization of X-ray photoemission","authors":"Z.B. Chen ,&nbsp;P.F. Liu ,&nbsp;Y.Y. Qi ,&nbsp;G.P. Zhao ,&nbsp;H.Y. Sun","doi":"10.1016/j.hedp.2025.101193","DOIUrl":"10.1016/j.hedp.2025.101193","url":null,"abstract":"<div><div>In this manuscript, we calculate the spectral properties and the electron-impact excitation cross sections in the semiclassical dense hydrogen plasmas, by solving the modified relativistic Dirac equation based on the Dirac-Coulomb Hamiltonian and using the suggested relativistic distorted wave method, respectively. The obtained cross sections are then used to study the polarization of the de-excitation X-ray photoemission, which allows a deeper probe of the electronic structural properties of the atoms/ions, thus yielding a comprehensive understanding of the underlying atomic processes. We employ the effective model potential proposed by Ramazanov et al. (2015) to replace the electron-nucleus Coulomb potential, where the former (potential) is derived for general two interacting charged particles taking into account the quantum mechanical and screening effects in semiclassical dense plasmas. Relativistic effects, including the Breit interaction and dominant quantum electrodynamics corrections, are included. Our study involves a comprehensive investigation of the screening effect of the plasma ions on the various properties such as the bound state energies, excitation energies, transition rates, electron-impact excitation cross sections and subsequent polarizations of X-ray photoemission across a wide range of plasma parameters. We compare our numerical results with other available experimental and theoretical data, showing good agreement. The outcomes of this work not only help to better understand the fundamental properties of plasmas, but also provide important applications in fusion, astrophysics, and other fields.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101193"},"PeriodicalIF":1.6,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734751","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":"Siegert-pseudostate formulation with B-splines","authors":"H.B. Tran Tan,&nbsp;C.J. Fontes,&nbsp;C.E. Starrett","doi":"10.1016/j.hedp.2025.101191","DOIUrl":"10.1016/j.hedp.2025.101191","url":null,"abstract":"<div><div>Siegert states (SSs) serve as a useful basis for studying quantum scattering from finite-range potentials. Since they form a discrete instead of continuous set of eigen-solutions, SSs are convenient for performing electronic structure calculations in atoms, molecules, and plasmas. Numerical instabilities may arise, however, in the computation of SSs if the potential vanishes for some extended region, a situation commonly occurring in plasma calculations. In this paper, we identify the cause of these instabilities as the use of non-localized radial basis functions. We thus advocate the use of localized radial basis functions, in particular B-splines, for more robust computations of SSs.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101191"},"PeriodicalIF":1.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760872","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":"Exploring the generalized fifth-order (2 + 1)-dimensional KdV equation: The lump structures and collision phenomena to the shallow water under gravity and nonlinear lattice","authors":"Usman Younas ,&nbsp;Tukur Abdulkadir Sulaiman ,&nbsp;Hajar Farhan Ismael ,&nbsp;Patient Zihisire Muke","doi":"10.1016/j.hedp.2025.101186","DOIUrl":"10.1016/j.hedp.2025.101186","url":null,"abstract":"<div><div>This study deals the lump structures and interaction phenomena to the (2 + 1)-dimensional generalized fifth-order KdV (2GKdV) equation which demonstrates long wave movements under the gravity field and in a two-dimensional nonlinear lattice in shallow water. A variety of solutions like lump periodic, collision between lumps and hyperbolic solutions as well as exponential solutions, breather waves, two wave solutions are under consideration. The Hirota perturbation expansion technique with setting nonzero background wave has been adopted for investing the studied model and securing the solutions. A lump solution is a rational function solution which is real analytic and decays in all directions of space variables. Breather waves refer to solitary waves that exhibit both partial localization and periodic structure in either space or time. Breathers serve crucial functions in nonlinear physics and have been observed in various physical domains, including optics, hydrodynamics, and quantized superfluidity. The specified parameter values produce a variety of graphs with distinctive shapes to visually represent the results. The technique’s performance, clarity, and visibility are highlighted in its suitability for various nonlinear equations in computational physics and other research domains, illustrating collision-related components and solution properties.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101186"},"PeriodicalIF":1.6,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679262","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":"Evaluation of circular geodesics and thermodynamics of a Bumblebee gravity-like black hole","authors":"Riasat Ali ,&nbsp;Terkaa Victor Targema ,&nbsp;Xia Tiecheng ,&nbsp;Rimsha Babar","doi":"10.1016/j.hedp.2025.101189","DOIUrl":"10.1016/j.hedp.2025.101189","url":null,"abstract":"<div><div>In this study, we explore the thermodynamic and geodesic stability of Reissner–Nordström (RN) black holes within the framework of Bumblebee gravity (BG), a Lorentz-violating extension of general relativity (GR). By examining the black hole’s mass distribution and horizon thermodynamics, we establish that although charged black holes in BG exhibit local stability, they remain globally unstable. This conclusion is substantiated by the positive-definite Gibbs free energy and the negative-definite Hessian matrix, which collectively indicate a fundamental instability in the system’s global equilibrium. We utilized the effective potential to derive the Lyapunov exponents for both time-like and null geodesics, assessing their stability. We found that the circular orbits beyond the innermost stable circular orbits in the Schwarzschild regime are stable, which contrasts with the RN black hole solution in GR. Furthermore, our findings demonstrate that a strong Bumblebee field induces unstable orbits. We establish that extreme RN black holes in Einstein gravity do not possess quasi-normal frequencies and instead exhibit stable, constant perturbations. In the non-extremal case, perturbations settle into a steady state, maintaining a constant amplitude. This behavior parallels observations made in the context of the Bumblebee effect.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101189"},"PeriodicalIF":1.6,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679259","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":"Electron density in air laser plasma created by femtosecond pulses of laser radiation","authors":"I.A. Zyatikov,&nbsp;V.F. Losev","doi":"10.1016/j.hedp.2025.101190","DOIUrl":"10.1016/j.hedp.2025.101190","url":null,"abstract":"<div><div>The results of experimental studies of electron density in air laser plasma, created by femtosecond radiation pulse at the wavelength of 950 nm and 60 fs duration are presented. Laser pulse was focused by lens with focal lengths from 15 to 100 cm to create a laser plasma. Electron density was determined from specific deposited energy in plasma. It is shown that when changing the specific deposited energy from 0.4 to 10 J/cm³ the electron density in plasma changes from 1.7⸱10¹⁷ to 3.9⸱10¹⁸ cm⁻³. Qualitative estimates of ionization mechanisms based on calculations of Keldysh parameter are carried out. It is shown that in our experimental conditions the main mechanism is multiphoton ionization.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101190"},"PeriodicalIF":1.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679260","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":"Study of cosmic parameters and thermodynamics of higher dimensional Einstein Chern–Simons cosmology through Barrow entropy","authors":"A. Jawad ,&nbsp;Nadeem Azhar ,&nbsp;Warisha ,&nbsp;N. Myrzakulov ,&nbsp;K. Yerzhanov ,&nbsp;S. Myrzakul","doi":"10.1016/j.hedp.2025.101187","DOIUrl":"10.1016/j.hedp.2025.101187","url":null,"abstract":"<div><div>In this paper, we assume a flat FRW universe in the context of the five-dimensional Einstein Chern–Simons theory of gravity. We take into account the Barrow holographic dark energy density with the Hubble horizon is the boundary of the universe to study the cosmic evolution of the universe. We discuss various cosmological parameters such as the coincidence parameter, density parameter, equation of state parameter, and deceleration parameter. Moreover, we explore thermal stability within the context of this scenario. We consider the Barrow holographic dark energy model with both interacting and non-interacting scenarios of dark components to evaluate these parameters and thermal stability. We plot the coincidence parameter, which displays a DE-dominated phase of the universe. It is interesting to mention here that we obtain some consistent results representing the accelerated expansion of the universe.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101187"},"PeriodicalIF":1.6,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143641956","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":"Estimate calculation of discrete energy levels in the hydrogen atom using an indeterministic method","authors":"Usama Afzal","doi":"10.1016/j.hedp.2025.101192","DOIUrl":"10.1016/j.hedp.2025.101192","url":null,"abstract":"<div><div>In the present study, we use the indeterministic method based on uncertainty conditions to estimate the discrete energy levels of hydrogen atoms. We analyze in detail how transitions from the ground state (<em>n</em> = 1) to the first excited state (<em>n</em> = 2) occur by dividing into sub-states and introducing the indeterminacy concept. The calculated energy levels expressed that as the indeterminacy changes, the energy level increases from -13.60 eV to -3.40 eV and there is observed a decrease in energy required to transition from each sub-state to <em>n</em> = 2. Such as for the transition from <em>n</em> = 1.1 to <em>n</em> = 2.0 there is a need for 9.18 eV. As a result, it is found that our new approach exploits the uncertainty principle to reveal deep trends in the energy transition. This work has significant implications for atomic physics and energy applications, spectroscopy and quantum mechanics. Our findings demonstrate the potential of imprecise data to contribute significantly to scientific understanding.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101192"},"PeriodicalIF":1.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679261","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":"Cosmological implications and ghost dark energy model in f(Q,C) gravity","authors":"M. Sharif ,&nbsp;M. Zeeshan Gul ,&nbsp;M. Hassan Shahid","doi":"10.1016/j.hedp.2025.101185","DOIUrl":"10.1016/j.hedp.2025.101185","url":null,"abstract":"<div><div>The primary purpose of this work is to examine the ghost dark energy model in the framework of <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> gravity, where <span><math><mi>Q</mi></math></span> denotes the non-metricity and <span><math><mi>C</mi></math></span> defines the boundary term. For this objective, we examine a flat Friedmann–Robertson–Walker spacetime containing an ideal matter distribution. We investigate a scenario involving interacting fluids that include both dark energy and dark matter in this framework. Further, we reconstruct <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> functional form to analyze the effects of this modified approach on the development of the cosmos. The reconstructed <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> model reveals an increasing behavior for both non-metricity and redshift functions, indicating a viable cosmological model. We explore the behavior of various cosmic parameters with respect to different parametric values. The positive energy density and negative pressure suggest that the universe is in the accelerated expansion phase. The equation of state parameter falls in the phantom region, aligning with observational data. Additionally, the increasing behavior in the (<span><math><mrow><msub><mrow><mi>ω</mi></mrow><mrow><mi>D</mi></mrow></msub><mo>−</mo><msubsup><mrow><mi>ω</mi></mrow><mrow><mi>D</mi></mrow><mrow><mo>′</mo></mrow></msubsup></mrow></math></span>)-plane indicates a freezing region, the <span><math><mrow><mo>(</mo><mi>r</mi><mo>−</mo><mi>s</mi><mo>)</mo></mrow></math></span>-plane behavior corresponds to the Chaplygin gas model, reinforcing the model’s compatibility with current cosmological observations. This work provides new insights into the relationship between dark energy models and modified gravity theory, enhancing our understanding of cosmic evolution. Our findings align with the existing observational data (Ade et al., 2016), demonstrating that <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> model accurately describes the dark energy and cosmic evolution.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101185"},"PeriodicalIF":1.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679381","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":"Overview of oxygen opacity experiments at the national ignition facility and investigation of potential systematic errors","authors":"D.C. Mayes ,&nbsp;B.A. Hobbs ,&nbsp;R.F. Heeter ,&nbsp;T.S. Perry ,&nbsp;H.M. Johns ,&nbsp;Y.P. Opachich ,&nbsp;M. Hohenberger ,&nbsp;P.A. Bradley ,&nbsp;E.C. Dutra ,&nbsp;C.J. Fontes ,&nbsp;E. Gallardo-Diaz ,&nbsp;M.H. Montgomery ,&nbsp;H.F. Robey ,&nbsp;M.S. Wallace ,&nbsp;D.E. Winget","doi":"10.1016/j.hedp.2025.101177","DOIUrl":"10.1016/j.hedp.2025.101177","url":null,"abstract":"<div><div>Experiments to measure oxygen opacity at stellar interior conditions have been performed at the National Ignition Facility in a Discovery Science campaign. These experiments utilize the Opacity-on-NIF platform with a sample comprised of O, Mg, and Si. The spectral data from the Opacity Spectrometer cover the 1000–2000 eV photon energy range showing bound-free continuum absorption from O and line absorption from Mg and Si. DANTE and the Gated X-ray Detector are employed to measure the sample plasma’s temperature and density, respectively. Initial data show lower transmission than expected by theoretical models, raising questions of whether potential background or data uniformity concerns could produce systematic errors in the inferred transmission. Here, we investigate three concerns thought to be important for the oxygen opacity data, including instrumental scattered background, sample self-emission non-uniformity, and backlight continuum non-uniformity. Additionally, we show the effect of a recently developed method to account for 2nd order crystal reflection. The total effect of these concerns on one experiment is found to be small compared to the observed difference between the inferred transmission and a model calculation at the inferred temperature and density. Thus, we conclude that these potential sources of systematic error cannot account for the observed difference, increasing the likelihood of a real effect due to the high temperature and density conditions. However, because this is only a single experiment, we cannot make a firm conclusion. More experiments measuring the opacity and necessary calibrations are needed to assess the reproducibility and uncertainty of this result.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101177"},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534747","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}