The exchange interaction, a fundamentally quantum-mechanical phenomenon, can significantly modify the classical description of cold, overdense plasmas. These quantum effects can be systematically analyzed within the framework of quantum magnetohydrodynamic (QMHD) theory, which enables the use of separate momentum equations for spin-up and spin-down electron populations. In this study, we adopt this approach to incorporate exchange interactions for both spin species and investigate the excitation of ion-acoustic wave (IAW) solitons in the plasma system. Using a perturbative expansion method, the governing equations are reduced to a nonlinear Schrödinger equation (NLSE), which admits solitonic wave solutions. The stability of these solitons is examined through a detailed analysis of the corresponding dispersion relation, revealing the conditions for modulational instability, whereby small perturbations within the wave envelope can grow over time. The results show that the growth rate of modulational instability increases with soliton velocity and initial potential amplitude, while exhibiting a nonmonotonic dependence on the spin-polarization ratio, reaching a maximum at the intermediate value of κ = 0.4$. An exact analytical expression for the soliton solutions is derived, and the effects of key model parameters on the properties and propagation characteristics of the solitons are systematically investigated.
We derive several equations of state for different types of energy from the first law of thermodynamics. We derive the equation of state of a Machian universe from the well-known energy formulaE=mc2. This equation of state is consistent with previously reported results. We then propose hypothetical forms of energy that lead to the equations of state of the Chaplygin gas, generalized Chaplygin gas, and modified Chaplygin gas. We also obtain the energy density of the Chaplygin gas by dividing the hypothetical energy by the volume of the universe, and find that it is consistent with previously reported results. Finally, we consider a toy model of energy.
Cavity optomechanics explores the interaction between light confined in optical cavities and mechanical oscillators, primarily driven by radiation pressure forces. These interactions enable significant advances in precision measurements, quantum information processing, and tests of fundamental quantum mechanics. This paper presents a detailed analysis of membrane vibration and radiation pressure force within a cavity optomechanical system. The membrane's equation of motion is derived, the radiation pressure force is evaluated within the Lorentz force formalism, and the corresponding interaction Hamiltonian is formulated. Quantization of the resulting Hamiltonian enables the investigation of quantum phenomena, including entanglement generation and quantum state transfer, and provides further insight into emerging applications and future research directions in cavity optomechanics.
New experimental data on the elastic scattering of the nuclear process 15N+11B at an energy of Elab=26.25 MeV were obtained on the DC-60 cyclotron of the INP RK. Based on a semi-microscopic analysis of the interaction of an accelerated 15N ion with 1p-shell nuclei 11B the effectiveness of the new B3Y-Fetal potential was studied. . The difference between the B3Y-Fetal potential and the traditional Yukawa potentials (M3Y-Reid and M3Y-Paris) is that its density-dependent parameters are determined from the saturation condition of nuclear matter at low energy. Analysis was performed on double folding optical model (DFOM) and so no for other acronyms. The real potential of semi-microscopic analysis was calculated on the matrix of effective NN - interactions by the density of nucleon distribution in the overlapping region of the colliding nuclei. The density C, α, β, γ - dependent parameters included in the effective NN interaction are calculated at the optimal K - incompressibility factor values. As a result of the analysis of the experimental data for the 15N+11B system, the optimal parameter values for the elastic scattering cross-section were determined. The effectiveness of the B3Y-Fetal potential used to increase the saturation property of the nuclear substance is determined by the Nr - renormalization factor of semi-microscopic analysis and the χ2/N - comparison factor with the experimental cross-section.
An exact analytical solution to a three-state photophysical model is presented to explicitly map the time-resolved fluorescence dynamics of a fluorophore under pulsed excitation. As distinct from earlier analytical treatments that primarily focused on transient absorption and total ground-state depletion, the proposed eigenvalue-eigenvector framework captures both transient and steady-state emission responses. The photophysical model accounts for electronic transitions between the singlet ground state, the excited singlet state and a long-lived triplet state, enabling a treatment of excitation, radiative decay, intersystem crossing, together with triplet-state relaxation. By diagonalizing the rate matrix consisting of phenomenological transition rates, closed-form expressions for the time-dependent and steady-state populations are obtained, revealing a clear separation of time scales governing fluorescence dynamics. The analytical solution is then applied to the rhodamine-based CF640R dye with an aim to investigate population redistribution as a function of arbitrary pulse duration and excitation irradiance in the nanosecond-to-millisecond time window. The computational results demonstrate that pulsed excitation enables the resolution of triplet-state dynamics, which strongly influence the excitation-dependent fluorescence behavior arising from the singlet excited state. Beyond the specific case of CF640R, the presented analytical treatment establishes a general and physically adaptive framework for analyzing excitation-duration and irradiance-dependent fluorescence behavior of diverse fluorescent chromophores with long-lived, nonemissive electronic states in condensed phases.
This paper presents the horizontal solar radiation data for Osmaniye (37◦04′N, 36◦22′E), located in Mediterranean region of Türkiye, over the period 2014–2023. Solar radiation variability, recorded at 1-min intervals, was evaluated in terms of hourly, daily, monthly, seasonal, and annual averages. Over the 10-year periods, the mean daily total and daily average global radiations received on a horizontal surface were 1,360,000 W/m2 and 371.47 W/m2, respectively. The monthly averaged daily global radiation (averaged over the 10-year period) ranged from 202.94 W/m2 in December to 496.86 W/m2 in July. The seasonal average values of solar radiations were 452.14 W/m2 in summer, 394.40 W/m2 in autumn, 353.19 W/m2 in spring, and 202.51 W/m2 in winter. The annual average clearness index ranged from 0.43 in December to 0.61 in June, with an overall mean of 0.55. In addition, the present measurements were compared with the NASA solar energy model based on a 36-year average (1987–2022). The performance between present measurement and the NASA data was evaluated using statistical metrics (R2, RMSE, MBE, and t-statistic), yielding values of 98.77%, 29.41 W/m2 20.15 W/m2, and 3.12, respectively. The measured data are generally consistent with the NASA data, with some discrepancies. Overall, the results indicate that Osmaniye Province, located on the Mediterranean coast of Türkiye, receives abundant solar radiation and therefore has strong potential for solar energy development. This paper presents the horizontal solar radiation data for Osmaniye (37◦04′N, 36◦22′E), located in Mediterranean region of Türkiye, over the period 2014–2023. Solar radiation variability, recorded at 1-min intervals, was evaluated in terms of hourly, daily, monthly, seasonal, and annual averages. Over the 10-year periods, the mean daily total and daily average global radiations received on a horizontal surface were 1,360,000 W/m2 and 371.47 W/m2, respectively. The monthly averaged daily global radiation (averaged over the 10-year period) ranged from 202.94 W/m2 in December to 496.86 W/m2 in July. The seasonal average values of solar radiations were 452.14 W/m2 in summer, 394.40 W/m2 in autumn, 353.19 W/m2 in spring, and 202.51 W/m2 in winter. The annual average clearness index ranged from 0.43 in December to 0.61 in June, with an overall mean of 0.55. In addition, the present measurements were compared with the NASA solar energy model based on a 36-year average (1987–2022). The performance between present measurement and the NASA data was evaluated using statistical metrics (R2, RMSE, MBE, and t-statistic), yielding values of 98.77%, 29.41 W/m2 20.15 W/m2, and 3.12, respectively. The measured data are generally consistent with the NASA data, with some discrepancies. Overall, the results indicate that Osmaniye Province, located on the Mediterranean coast of Türkiye, receives abundant solar radiation and therefore has strong potential for solar energy development.
This study presents an evaluation of derivative-free optimization algorithms for the direct minimization of Hartree-Fock-Roothaan energy functionals involving nonlinear orbital parameters and noninteger-order quantum numbers. The analysis focuses on atomic calculations employing noninteger Slater-type orbitals. Analytic derivatives of the energy functional are not readily available for these orbitals. Four methods are investigated under identical numerical conditions: Powell's conjugate-direction method, the Nelder-Mead simplex algorithm, coordinate-based pattern search, and a model-based algorithm utilizing radial basis functions for surrogate-model construction. Performance analysis is first carried out using the Powell singular function, a well-established test case exhibiting challenging properties, including Hessian singularity at the global minimum. The algorithms are then applied to Hartree-Fock-Roothaan self-consistent-field energy functionals, which define a highly nonconvex optimization landscape due to the nonlinear coupling of orbital parameters. Illustrative examples are provided for closed-shell atomic configurations, specifically the He and Be iso electronic series, with calculations performed for energy functionals involving up to eight nonlinear parameters. This work presents the first systematic investigation of derivative-free optimization methods for Hartree-Fock-Roothaan energy minimization with noninteger Slater orbitals.
The problem of identifying additional local integrals of motion in generic three-dimensional potentials remains a fundamental issue in dynamical systems and galactic dynamics, since most realistic gravitational fields lack global symmetries or separable coordinate systems. In this study, we propose a general constructive method for deriving such local integrals by introducing auxiliary functions whose gradients define an orthogonal frame adapted to the potential. The central idea is that the velocity field can be characterized by two quadratic algebraic relations whose compatibility conditions uniquely determine the orthogonal frame and ensure the existence of two additional isolating integrals. Our main results include: (i) the derivation of the complete set of necessary and sufficient compatibility conditions for these auxiliary functions; (ii) the proof that these functions generate two independent local quadratic integrals in addition to the energy integral; and (iii) the explicit construction of the associated orthogonal coordinate systems. The novelty of the proposed method lies in its unified nonperturbative framework, which does not rely on global separability, in contrast to classical St & auml;ckel theory and existing approximation-based approaches. Applications to ellipsoidal and spherical coordinate systems demonstrate that the method recovers known global integrals in separable cases while also yielding new classes of local integrals for more general potentials. Consequently, the proposed framework extends the class of partially integrable models relevant to celestial mechanics and stellar dynamics.
Wave attractors in viscous media exhibit laminar or turbulent behavior, dictated by the intensity of the external forcing. Laminar attractors are often assumed to behave as linear systems. However, existing studies typically focus on fully developed flows, neglecting the dynamic formation process of these attractors. This simplification overlooks crucial transient phenomena that govern their emergence and stability. In this paper, first, we investigate unconventional wave attractor configurations subjected to forcing with a complex spectrum, which lead to early nonlinearity demonstration. Next, we focus on the transient processes of attractor formation and destruction, providing insights into their dynamic evolution. Furthermore, we identify temporal and velocity scaling relationships across various viscosity parameters, revealing the self-similar behavior inherent in these wave-attractor systems.
This paper presents a novel framework for solving two-dimensional (2D) inverse scattering problems by integrating nonuniform rational B-spline (NURBS) parameterization with convolutional neural networks (CNNs). Traditional pixel/voxel-based deep learning methods often suffer from high dimensionality and discretization artifacts, while purely geometric approaches lack robust inversion mechanisms. To address these limitations, we propose a hybrid framework where the relative permittivity profile of an unknown scatterer is compactly represented as a NURBS surface, parameterized by a sparse set of control points and weights. This approach reduces the problem dimensionality over 16 times. On the other hand, using NURBS expansion ensures material continuity. The scattered electric and magnetic fields are simulated using the 2D finite-difference time-domain (FDTD) method, and a CNN is trained to map time-domain scattered field measurements probed around the device under test, directly to the NURBS control points. The results demonstrate that the framework achieves accurate reconstructions, with a root mean squared error of 0.012, while maintaining computational efficiency and robustness to noise.
This paper presents the horizontal solar radiation data for Osmaniye (37 degrees 04 ' N, 36 degrees 22 ' E), located in Mediterranean region of T & uuml;rkiye, over the period 2014-2023. Solar radiation variability, recorded at 1-min intervals, was evaluated in terms of hourly, daily, monthly, seasonal, and annual averages. Over the 10-year periods, the mean daily total and daily average global radiations received on a horizontal surface were 1,360,000 W/m2 and 371.47 W/m2 , respectively. The monthly averaged daily global radiation (averaged over the 10-year period) ranged from 202.94 W/m2 in December to 496.86 W/m2 in July. The seasonal average values of solar radiations were 452.14 W/m2 in summer, 394.40 W/m2 in autumn, 353.19 W/m2 in spring, and 202.51 W/m2 in winter. The annual average clearness index ranged from 0.43 in December to 0.61 in June, with an overall mean of 0.55. In addition, the present measurements were compared with the NASA solar energy model based on a 36-year average (1987-2022). The performance between present measurement and the NASA data was evaluated using statistical metrics (R2, RMSE, MBE, and t-statistic), yielding values of 98.77%, 29.41 W/m2 20.15 W/m2 , and 3.12, respectively. The measured data are generally consistent with the NASA data, with some discrepancies. Overall, the results indicate that Osmaniye Province, located on the Mediterranean coast of T & uuml;rkiye, receives abundant solar radiation and therefore has strong potential for solar energy development.
The research on two-dimensional (2D) materials which have intrinsic magnetism and exotic electronic structures is an important quest in condensed matter physics. The Lieb lattice offers a unique platform for studying strongly correlated electron phenomena. In this work, we systematically investigated the structural, dynamical, mechanical, electronic, and magnetic properties of monolayer transition metal tetrafluorides (MF4, where M = Ag, Cd, Cr, Cu, Fe, Hf, Mn, Mo, Nb, Ni, Pd, Pt, Rh, Ru, Sc, Ta, Ti, V, W, and Y) arranged in a 2D Lieb lattice, using first-principles calculations based on density functional theory (DFT) with Hubbard (U) corrections. Our calculations showed the dynamical stability of three candidates (MoF4, NbF4, and TaF4) within this materials family through phonon dispersion analysis, and they were also found to be mechanically stable. To investigate their electronic structure, scalar-relativistic (No-SOC) and fully relativistic (SOC) electronic band structures were calculated. As a result, MoF4, NbF4, and TaF4 are found to be metallic. While SOC effects are negligible in MoF4, a pronounced Rashba/Dresselhaus-type splitting is observed in NbF4 and TaF4. This significant splitting, resulting from the heavy elements (Nb, Ta) and broken inversion symmetry inherent to the monolayer Lieb lattice confirms strong relativistic effects. We showed that these monolayers exhibit antiferromagnetic (AFM) properties, and TaF4 has the highest Neel temperature (180 K). The coexistence of 2D antiferromagnetism and electronic properties makes the MF4 Lieb Lattice monolayers promising candidates for applications in next-generation spintronic devices.
The Poisson problem in the space outside of a disk is investigated. Specifically, the Green's function corresponding to the problem is calculated. The Green's function equation is separable in terms of (oblate) ellipsoidal coordinates. Therefore, these coordinates are used to obtain a series expression for the Green's function. This is done for both the Dirichlet and Neumann problems. The result is used to calculate the electric potential for some examples, with specific boundary conditions on a disk.
Near-infrared (NIR) emitters operating in the 650-900 nm range are highly attractive for imaging and sensing in turbid media; however, cadmium-free InP-based quantum dots (QDs) often suffer from limited brightness due to nonradiative pathways and inefficient photon outcoupling. In particular, heterostructured InP QDs can exhibit band alignments that induce partial spatial separation of charge carriers, leading to reduced electron-hole wavefunction overlap. This modifies intrinsic recombination dynamics and enhances the sensitivity of their emission to the surrounding photonic environment. Here, we investigate silver toroidal plasmonic nanoantenna dimers (Ag TPNDs) through finite-difference-time-domain (FDTD) simulations as a geometry-tunable platform for enhancing NIR emission of heterostructured InP-based QDs. The coupled toroidal geometry supports strongly confined bonding modes that generate intense nanogap hotspots, while its resonance can be systematically tuned through the toroid aspect ratio. By spectrally aligning the antenna response with QD emission bands (675-845 nm), we achieve large Purcell enhancements together with high quantum efficiencies, demonstrating efficient conversion of enhanced decay rates into radiative emission. We further show that nanometer-scale variations in emitter-antenna separation strongly modulate the radiative rates and spectral response. These results establish toroidal plasmonic nanodimers as a topology-driven platform for controlling emission in NIR quantum emitters and for advancing NIR nanophotonic applications.
The optical textures of a uniform liquid crystal (LC) molecule lattice structure were explored through Monte Carlo simulations, combined with Mueller matrix (MM) formalism and Newton's color theory. These simulations utilized a Lebwohl-Lasher type interacting LC lattice under periodic boundary conditions, generating ensemble-averaged configurations at two temperature regimes (kBT = 0.9 and 1.2), corresponding respectively to nematic and isotropic states. These configurations were then incorporated into the MM framework to evaluate the polarization states of transmitted light. To visually interpret the resulting interference phenomena, we propose a new visualization method based on a modern interpretation of Newton's color model. The Newton color model was employed to render the emerging patterns on a two-dimensional screen in an intuitive fashion. We further introduce a transmittance saturation model as a function of thickness (Lz), which provides a good fit to the transmittance data of anisotropic media in a uniform LCM lattice. The model, T (Lz) = T0[ 1-exp(-kappa Lz)], successfully captures how transmittance varies with lattice thickness. Interference hues and texture distributions shifted noticeably with increasing thickness in both nematic and isotropic phases, reflecting the degree and nature of molecular ordering. The nematic textures exhibited a rich, broad color spectrum, whereas the isotropic textures were characterized by fewer chromatic variations. Moreover, increasing thickness significantly enhanced both light intensity and color diversity. The nematic textures appeared more structured and patchy, indicative of partial molecular alignment. These findings underscore the intricate interplay among molecular ordering, optical phase distinctions, and overall LC behavior, offering valuable perspectives for display technologies, optical sensing, and related photonic applications that demand fine control of LCM birefringence.
The scalar hybrid meson Hbc , containing both heavy b and c quarks, represents an intriguing exotic state in QCD. In this article, we investigate its strong decay properties using three-point QCD sum rules. We focus on the two leading decay channels, Hbc B+D0 and Hbc B0D+, which are expected to dominate the decay dynamics. The B and D mesons produced in these decays each consist of one heavy and one light quark. The strong coupling constants at the corresponding vertices are extracted, and the partial decay widths of both channels are found to be approximately equal, around (38.54 +/- 9.80) MeV, with a total width of (77.08 +/- 13.86) MeV for these dominant decays. Borel transformation and continuum subtraction are applied to ensure the convergence of the sum rules and to suppress higher resonance contributions. These results indicate that the two channels provide a substantial contribution to the decay of the Hbc meson. Our findings provide a reliable quantitative description of its decay dynamics, shed light on the internal structure and interactions of scalar hybrid mesons, and advance the theoretical understanding of heavy hybrid meson spectroscopy. Furthermore, the results offer valuable guidance for future experimental searches at facilities such as LHCb and Belle II.
We study the 1/c expansion of general relativity within a formulation that is compatible with both the Arnowitt-Deser-Misner and the Kol-Smolkin decompositions. The Einstein-Hilbert action takes a common form for those decompositions as they are dual to each other. We first develop a method to expand this generic form without choosing a particular slicing and then push the expansion up to c-3 order within this novel approach. Next, we apply our technique to the Arnowitt-Deser-Misner decomposition and expand it up to c-3 order explicitly. In order to demonstrate the applicability of our method and to highlight the duality at the level of expansion, we also perform the expansion in the Kol-Smolkin decomposition up to c-1 order. Lastly, we make some all-order observations.
New experimental data on the elastic scattering of the nuclear process 15N+ 11B at an energy of Elab =26.25 MeV were obtained on the DC-60 cyclotron of the INP RK. Based on a semimicroscopic analysis of the interaction of an accelerated 15N ion with 1p-shell nuclei 11B, the effectiveness of the new B3Y-Fetal potential was studied. The difference between the B3Y-Fetal potential and the traditional Yukawa potentials (M3Y-Reid and M3Y-Paris) is that its density-dependent parameters are determined from the saturation condition of nuclear matter at low energy. Analysis was performed on double folding optical model (DFOM) and so on for other acronyms. The real potential of semimicroscopic analysis was calculated on the matrix of effective NN-interactions by the density of nucleon distribution in the overlapping region of the colliding nuclei. As a result of the analysis of the experimental data for the 15N+ 11B, the optimal parameter values for the elastic scattering cross-section were determined. The effectiveness of the B3Y-Fetal potential used to increase the saturation property of the nuclear substance is determined by the Nr-renormalization factor of semimicroscopic analysis and the chi 2/N-comparison factor with the experimental cross-section.
A new phenomenological dark energy model, originally associated to the large-scale structure formation and considered as a solution to the fine-tuning and coincidence problems related to the cosmological constant, was analyzed within the framework of General Relativity in a Friedman-Robertson-Walker spacetime and its model parameters were estimated using cosmic chronometers and recent DESI data. It turns out that the proposed model can serve as an alternative evolving dark energy model with a novel equation of state function, apart from other popular propositions in the literature. Due to the form of this phenomenological energy density ansatz, which starts to rise with the nonlinear structure growth in the universe and falls with the domination of cosmic voids, we prefer to call it structure-induced dark energy. Observational constraints show that it is not only a suitable solution for the fundamental problems such as coincidence or fine-tuning problems, it gives flexibility, when considering the cosmic tensions and presents a new perspective on the evolving dark energy models.
We formulate a quantum-mechanical system consisting of a single discrete state coupled to an infinite ladder of equally spaced states, with the coupling described by a Lorentzian profile. Various limiting cases of this system correspond to well-known models in quantum optics: the narrow-resonance limit yields the Rabi model, the wide-resonance limit yields the Bixon-Jortner model, the wide-resonance true continuum limit yields the Wigner-Weisskopf model, and the fixed-resonance true continuum limit yields a system typically studied using methods developed by Fano. We obtain a semianalytical solution to the eigenvalue problem by reducing it to a transcendental equation and demonstrate the limiting behaviors described above. We then investigate numerically the dynamics of the initial discrete state and show that, in various limiting regimes, the system exhibits a wide range of behaviors predicted by the asymptotic theory, including exponential decay, revivals, Rabi oscillations, and damped oscillations. The ability of the system to interpolate between such a rich variety of behaviors and established model systems, together with the accessibility of a semianalytical solution, makes it a useful model in quantum optics and related fields.
