The European Physical Journal Plus最新文献

{"title":"Impedance effects on thermoelastic diffusive wave reflection with temperature-dependent properties under the MGT model","authors":"P. Sandhya Rani,&nbsp;Rajneesh Kumar,&nbsp;E. Rama","doi":"10.1140/epjp/s13360-026-07744-z","DOIUrl":"10.1140/epjp/s13360-026-07744-z","url":null,"abstract":"<div><p>This study investigates the reflection of plane waves in a thermoelastic diffusion medium governed by the Moore–Gibson–Thompson (MGT) heat conduction model, incorporating both impedance boundary conditions and temperature-dependent material properties. The governing field equations are formulated by coupling mechanical, thermal, and diffusive effects, and Helmholtz decomposition is employed to identify distinct longitudinal (P), transverse shear (SV), thermal (T), and diffusive (P₀) wave modes. Analytical expressions for reflection coefficients are derived, enabling a detailed examination of wave–boundary interactions under varying physical parameters. The results reveal that impedance parameters and temperature-dependent properties significantly influence reflection amplitudes and mode conversion, while thermal diffusion enhances the contribution of diffusive wave modes. Furthermore, the interplay between thermal relaxation and diffusion is shown to alter wave propagation characteristics in a non-trivial manner. These findings provide new insights into thermo-diffusive wave behavior and establish a more comprehensive framework for modeling wave propagation in advanced engineering and geophysical materials.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147830081","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":"Impact of the non-canonical approach to the exact solution of the ideal one-dimensional electron gas confined with an anisotropic quantum wire of oscillator-shaped profile","authors":"E. I. Jafarov,&nbsp;S. M. Nagiyev,&nbsp;J. Van der Jeugt","doi":"10.1140/epjp/s13360-026-07764-9","DOIUrl":"10.1140/epjp/s13360-026-07764-9","url":null,"abstract":"<div><p>We study an exactly solvable model that can be interpreted as an ideal one-dimensional electron gas confined with an anisotropic quantum wire potential of oscillator-shaped profile. The homogeneous nature of the quantum wire is broken by the introduction of the effective electron mass, which changes with radial distance. We solve the problem described both within the canonical and the non-canonical approach. Analytical expressions of the wavefunctions of the stationary states for both cases in terms of the Laguerre polynomials are obtained, as well as the discrete energy spectrum related to these wavefunctions. Additionally, an exact solution to the angular position part of the position-dependent mass Schrödinger equation within the non-canonical approach leads to the angular part wavefunctions of the even and odd states expressed through the Gegenbauer polynomials. Possible limit relations and special cases are studied too.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147830082","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":"Stochastic analysis of dynamical systems application in epidemic model with delay demonstration","authors":"Umar Shafique,&nbsp;Ali Raza,&nbsp;Marek Lampart,&nbsp;Faridah Alruwaili,&nbsp;Emad Fadhal","doi":"10.1140/epjp/s13360-026-07698-2","DOIUrl":"10.1140/epjp/s13360-026-07698-2","url":null,"abstract":"<div><p>The stochastic delay models provide the realistic way of investigating the infectious diseases. HFMD is a viral disease that affects children predominately, according to WHO and CDC. The main purpose is to study the transmission dynamics of Hand, Foot, and Mouth Disease (HFMD) through stochastic with delay approaches. How is stochastic delay the best strategy for studying the dynamics of disease in a population? For this, we consider the existing deterministic model in literature, with the whole population divided as susceptible S(t), exposed E(t), infected I(t), and recovered humans R(t). After that, we extend the deterministic framework to formulate a stochastic delay model by incorporating stochastic delay differential equations (SDDEs), utilizing transition probabilities and nonparametric perturbation techniques. The analysis rigorously investigates key properties such as positivity, boundedness, disease extinction, and persistence, alongside a thorough examination of the basic reproduction number and its critical role in the disease dynamics. The disease-free equilibrium (DFE) and endemic equilibrium (EE) are two states; local and global stability of second order and sensitivity analysis of parameters are analyzed to verify the model validations. Owing to the complex nonlinear nature of the stochastic delay differential equations in the model, we employed a variety of techniques including the standard Euler–Maruyama method, stochastic Euler, stochastic Runge–Kutta, and a stochastic nonstandard finite difference approach incorporating delays to visualize the results. Ultimately, a comparison of these methods is provided to highlight the superior effectiveness of the nonstandard stochastic methods when delay parameters are involved. This research improves our study of dynamics through stochastic with delay techniques version, which also opens up new directions for dynamical system dynamics and mathematical analysis. The comparison profiles were created for new solutions, and interaction behavior was plotted.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829923","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":"New analytical model of rotating black hole with dark matter halo: constraints from EHT observations and accretion disk","authors":"Uktamjon Uktamov,&nbsp;Sanjar Shaymatov,&nbsp;Bobomurat Ahmedov,&nbsp;Chengxun Yuan","doi":"10.1140/epjp/s13360-026-07740-3","DOIUrl":"10.1140/epjp/s13360-026-07740-3","url":null,"abstract":"<div><p>In this paper, we begin with a static black hole (BH) embedded in a Dehnen-type dark matter (DM) halo and apply the Newman–Janis algorithm (NJA) to construct a rotating black hole solution surrounded by a dark matter halo. We then examine the validity of the resulting spacetime geometry. Furthermore, we investigate the optical properties of a newly obtained rotating BH in the DM halo, including the geometrical structure of the black hole shadow, the light deflection angle using the Ono–Ishihara–Asada (OID) method, the photon sphere, and the dependence of the shadow radius on the DM halo parameters. Additionally, assuming that the spacetime of a supermassive black hole (SMBH) is described by the newly obtained rotating solution, we constrain the model parameters using shadow size measurements from the Event Horizon Telescope (EHT) and Gravity collaboration observations of M87<span>(^*)</span> and Sgr A<span>(^*)</span>. We further perform a Markov Chain Monte Carlo (MCMC) analysis to constrain the DM halo parameters <span>(rho _s)</span> and <span>(r_s)</span>, as well as the BH mass <i>M</i> and the spin parameter <i>a</i>. Our results show that the best-fit values of <span>(rho _s)</span> and <span>(r_s)</span> are consistent with previous results, supporting the physical reasonability of the proposed model considered here. Finally, we analyze the electromagnetic radiation flux from the rotating BH in the DM halo using a ray-tracing approach.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829755","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":"Quantum entanglement-driven modulation of spin transport in honeycomb ferromagnets","authors":"L. S. Lima","doi":"10.1140/epjp/s13360-026-07690-w","DOIUrl":"10.1140/epjp/s13360-026-07690-w","url":null,"abstract":"<div><p>We investigate how exchange interactions shape both quantum entanglement and the magnon Nernst effect in a two-dimensional ferromagnet on a honeycomb lattice. In particular, we examine how variations in the exchange parameters influence the spin Nernst coefficient and, in turn, modify the entanglement properties of the system. Entanglement negativity is employed as the primary quantifier of quantum correlations, providing a reliable measure for mixed states. Our analysis of the spin Nernst response shows that the coefficient vanishes at zero temperature, reflecting the absence of thermally excited magnons in this limit.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-07690-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829870","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":"Impact of MoS2-incorporation on the optical, electrical, and dielectric features of photoconductive bismuth phosphate glasses: enhanced photosensitivity and mixed ionic–polaronic conduction","authors":"Ali M. Ibrahim,&nbsp;Mashael S. Alghamdi","doi":"10.1140/epjp/s13360-026-07676-8","DOIUrl":"10.1140/epjp/s13360-026-07676-8","url":null,"abstract":"<div><p>The outstanding physicochemical properties of MoS₂ make it an excellent candidate for energy conversion and optoelectronic applications. Despite extensive research on MoS₂, there is no focus on the investigation of MoS₂-based glasses. The main goal is the enhancement of electrical, optical, and photoconductive features of sodium phosphate glasses through the reinforcement of molybdenum disulfide. The amorphous nature of the synthesized MoS₂-based phosphate glasses is confirmed by the XRD analysis. The optical absorption spectra demonstrate the promotion of non-bridging oxygens and reduction in optical band gap with the MoS₂ addition. The dc conductivity exhibits a reducing trend with MoS₂ addition, while the activation energy shows an increasing behavior. This indicates that the molybdenum ions cause a blocking effect by hindering the mobility of ions, reducing the conductivity. The photoconductivity and photosensitivity of MoS₂-based glasses increase with increasing the concentration of MoS₂ up to 4 mol%, and then they exhibit a slight decrease. The frequency and composition dependence of dielectric parameters is investigated. The dielectric constant exhibits an initial decline trend followed by an increasing behavior with the addition of MoS₂. It is demonstrated that the investigated glasses exhibit mixed ionic–polaronic conduction, coming from the movement of mobile sodium ions and the electron hopping between multivalent molybdenum ions. The highest photosensitivity of the glass with 4 mol% of MoS₂, which reaches a maximum value of 27.2, makes it a promising candidate for photodetection and optoelectronic devices.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829095","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 Vlasov bivector: a parameter-free approach to Vlasov kinematics","authors":"Finlay Gunneberg,&nbsp;Jonathan Gratus,&nbsp;Harvey Stanfield","doi":"10.1140/epjp/s13360-026-07703-8","DOIUrl":"10.1140/epjp/s13360-026-07703-8","url":null,"abstract":"<div><p>Plasma kinematics is typically performed on either the mass shell or a lab bundle, seven-dimensional phase spaces equipped with a Vlasov vector field. This choice of phase space encodes the parametrisation of the differential equations governing particle dynamics. By replacing the Vlasov vector field and related quantities over a phase space with a bivector on an eight-dimensional conic sub-bundle of the tangent bundle, we construct a parameter-free version of Vlasov theory. The advantages of this formalism include compatibility with light-like and ultra-relativistic particles, non-metric connections, and metric-free or pre-metric theories. Additionally, this formalism applies to theories where no time phase space can exist for topological reasons, e.g. when we wish to consider all geodesics, including space-like geodesics. We also use this formalism to derive a simple formula which enables the transformation of a Vlasov field from one phase space to another in such a way that the trajectories of the particles in the base space are unchanged. Our formalism also has implications for numerical simulations. By extending quantities such as the particle density form onto an eight-dimensional conic sub-bundle, we can extend existing numerical integrators, such as the agile numerical\u0000integrator, to relativistic scenarios. The extension of the particle density form also allows for the generalisation of the current 3-form onto the conic bundle. We also discuss the complicated relationship between the stress–energy form and phase space, how our formalism illustrates this, and the corresponding challenges in developing a parameter-free Einstein–Vlasov system. The relationship between our formalism and sprays or semi-sprays is explored, and examples from Finsler geometry are given.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-07703-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829150","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":"Microwave-tunable vacuum-induced photonic spin hall effect in a (Delta)-system","authors":"Muqaddar Abbas,&nbsp;Hamid R. Hamedi","doi":"10.1140/epjp/s13360-026-07677-7","DOIUrl":"10.1140/epjp/s13360-026-07677-7","url":null,"abstract":"<div><p>We investigate the photonic Spin Hall Effect (PSHE) in an optical cavity containing a <span>(Delta)</span>-type three-level atomic ensemble, where transparency is generated intrinsically by the quantized cavity vacuum field through vacuum-induced transparency (VIT). Building on this mechanism, we introduce and analyze a vacuum-induced PSHE, in which the transverse spin-dependent shift of the reflected probe beam arises solely from vacuum–atom coupling, thereby strengthening the underlying spin–orbit interaction. We further demonstrate that applying a weak microwave field to the lower atomic transition enables active, high-precision tuning of the vacuum-induced PSHE magnitude. The displacement is also shown to depend sensitively on the intracavity photon number, providing an additional degree of quantum control over spin-resolved beam dynamics. Finally, we extend our study to include Doppler broadening, revealing how thermal motion modifies the susceptibility and alters the characteristic spin-dependent shifts. The combined results uncover key aspects of vacuum-mediated light–matter interactions in <span>(Delta)</span>-systems and establish a versatile framework for manipulating the PSHE in cavity-based quantum electrodynamics platforms.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829739","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":"Optimization of the limits of detection and quantitation on pulsed compact neutron systems – the cases of chlorine and sulfur in cementitious media","authors":"Cristina Macia-Castello,&nbsp;Daniel Blanco,&nbsp;Mattia Gaboardi,&nbsp;Jorge S. Dolado,&nbsp;Yasuo Wakabayashi,&nbsp;Tomonori Fukuchi,&nbsp;Yujiro Ikeda,&nbsp;Yoshie Otake,&nbsp;Felix Fernandez-Alonso","doi":"10.1140/epjp/s13360-026-07766-7","DOIUrl":"10.1140/epjp/s13360-026-07766-7","url":null,"abstract":"<div><p>The use of pulsed compact neutron systems to implement energy-resolved prompt-gamma activation analysis is herein assessed in detail for the quantitative and non-intrusive detection of chlorine and sulfur in cementitious media, two exogenous contaminants commonly found in buildings, civil infrastructures, or archeological artifacts. To this end, we have examined the current capabilities of the RIKEN RANS-I pulsed source across its neutron energy spectrum using its room-temperature moderator. We achieve up to a threefold improvement relative to previously reported limits of detection via the selective use of the <span>(gamma)</span>-ray yield in the wavelength interval 2-4 Å. Under these conditions, measurement times of a few minutes are sufficient to attain sensitivities in the sub-millimol%, and this figure can be improved further via the optimization of the existing detection system. Monte Carlo simulations of a validated model of RIKEN RANS-I show that order-of-magnitude gains in sensitivity are also within reach via the use of cold moderators, such as those based on solid methane or mesitylene. Altogether, these developments would enable limits of detection in the <span>(mu)</span>mol% range.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-07766-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829093","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":"The determinant representation of N-fold Darboux transformation of Kaup–Kupershmidt equation","authors":"Shuzhi Liu,&nbsp;Deqin Qiu","doi":"10.1140/epjp/s13360-026-07734-1","DOIUrl":"10.1140/epjp/s13360-026-07734-1","url":null,"abstract":"<div><p>We construct a Darboux transformation (DT) for a matrix-form linear spectral problem, which is related to the well-known Kaup–Kupershmidt (KK) equation. We present a detailed derivation of the one-fold DT for the KK equation, which offers a refinement of the original conclusion. Meanwhile, by means of multi-step iteration, we obtain the two-fold and <i>n</i>-fold DT of the KK equation, and then, the elements of the Darboux matrices are expressed by the ratios of two compact determinants. Based on the <i>n</i>-fold solution formula, the first-order and second-order dark soliton solutions have been constructed and their dynamical evolution has been discussed in detail.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829094","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}