The interaction of a V-type three-level atom with a single mode of electromagnetic field via multi-photon transitions is analytically solved via supersymmetric unitary operator approach. We have constructed the corresponding supersymmetric generators and performed the diagonalization of the Hamiltonian of the atomic system. The time evolution of the atom-field wave functions is derived in an exact

In this paper, we discuss remnants and quantum gravity effects on thermodynamics of a new kind of regular black hole known as Culetu black hole. The black hole results in coupling of gravity to nonlinear electrodynamic source. We first derive various thermodynamic quantities of interest. We then discuss in detail the existence and stability of remnants. The stability of remnants is then analyzed in

In this article, we show how the new Bogomolny’s equations for BPS vortices, with nonzero stress tensor, in the three-dimensional generalized Maxwell–Higgs model can be derived rigorously using the BPS Lagrangian method. Particularly, we add into the original BPS Lagrangian, which is a total derivative term, two additional terms that are proportional to square of the first derivative of scalar effective

The original version of this article containes a mistake. In the second line of Comment 2, it should read: “It is necessary to note that Schwarzschild metric is static while the rotating metric (which is the subject of discussion) is stationary.”

A more general (2+1)-dimensional Boussinesq equation with five arbitrary constants is studied. Multi-soliton solution, multi-breather solution, higher-order lump solution are obtained by employing the Hirota bilinear method and the long-wave limit approach. By selecting suitable value of parameters, the interaction mixed solutions are constructed, which are composed of three waves for lumps, breathers

The Editor-in-Chief has retracted this article [1]. Concerns were raised regarding the validity and physical implications of Section 3, and after following investigation, it has been determined that the article is invalid.

The study and characterization of an art work carried out by two or more artists is always an interesting challenge since each painter, although belonging to the same artistic current, can introduce specific pictorial materials or peculiar aesthetic effects, which constitute the artist fingerprint. This work presents a preliminary analytical study of the “Portrait of Mario Nuzzi”, painted by Giovanni

We study the resonance fluorescence in the Jaynes–Cummings model when nearby levels are taking into account. We show that the Stark shift produced by such levels generates a displacement of the peaks of the resonance fluorescence due to an induced effective detuning and also induces an asymmetry. Specific results are presented assuming a coherent and a thermal fields.

The modified field equations are written in logarithmic and power law versions of entropy corrected models in Einstein’s gravity in the background of FRW universe. In one section, a brief review of the Hořava–Lifshitz gravity is discussed and the modified field equations in logarithmic and power law versions of entropy corrected models in Hořava–Lifshitz gravity are formulated. The stability analysis

In this paper, we report about three cases of integrability in sense of Liouville for three-dimensional generalized Hénon–Heiles Hamiltonian. This also allow to get explicitly integrals of motions for each case. On the other hand, this paper investigates the phase space structure numerically with Poincaré surfaces of section and 3D projections which allow to verify that the analytical results are in

In this paper, some optical properties of a two-walled carbon nanotube are studied. The system is represented by two infinitely long and infinitesimally thin coaxial cylindrical shells, each containing a two-dimensional electron nano-fluid. The quasi-static approximation and the quantum hydrodynamic model are adopted in order to obtain the optical response of the system. General expressions for polarizability

We study light deflection from a Reissner–Nordström–de Sitter black hole in the gravitational monopole background. We first calculate the orbit equation and the contribution of the monopole and black hole parameters to the deflection angle up to second order for the vanishing cosmological constant case using the Rindler–Ishak method. We also obtain the contribution of the cosmological constant to light

Yang–Mills-like field theories are developed using both division quaternion and octonion algebras. Quaternionic field theory is the same as the Yang–Mills gauge theory. The octonionic field theory is an expansion from a similar field theory built with split octonions algebra that uses a complex-form basis as proposed by Gunaydin and Gursey (J Math Phys 14:1651, 1973), now with division octonions. This

In this work, we obtain a new interior solution supported by an anisotropic fluid in the framework of gravitational decoupling. To this end, we propose an non-standard anisotropy function to close the system of equations and we illustrate the method using the well-known Tolman IV model as a seed solution. The result is a well behaved anisotropic interior solution.

The Salerno model is a discrete variant of the celebrated nonlinear Schrödinger (NLS) equation interpolating between the discrete NLS (DNLS) equation and completely integrable Ablowitz–Ladik (AL) model by appropriately tuning the relevant homotopy parameter. Although the AL model possesses an explicit time-periodic solution known as the Kuznetsov–Ma (KM) breather, the existence of time-periodic solutions

This work deals with a class of square matrix nonlinear Schrödinger (MNLS) systems whose reductions include two equations that model hyperfine spin \(F = 1\) spinor Bose–Einstein condensates in the focusing and defocusing dispersion regimes, and two novel (mixed sign) equations that were recently shown to be integrable. Our main goal is to discuss the bright soliton solutions and their interactions

The exact non-static accelerating solutions of Einstein field equations in perfect fluid distribution with nonzero shear in the texture gas dominated universe corresponding to an indefinite non-degenerate metric in cartesian coordinates are obtained in a gravitational field of Petrov type D. Lie symmetry method is used for reduction and finding trigonometric solutions. By following multiplier approach

By using Monte Carlo simulations, we investigated a triangle double-layer graphene nanoisland with mixed-spin (3/2, 2) configuration. We focused on the effects of crystal-fields, exchange couplings, longitudinal magnetic fields, and temperature on the magnetic properties of the system. Various curves of magnetization, susceptibility, and internal energy as a function of temperature were obtained. We

In this paper, we present a new ansatz for solving equations of motion for the trapped orbits of the infinitesimal mass m, which is moving near the primary M3 in case of bi-elliptic restricted problem of four bodies (BiER4BP), where three primaries M1, M2, M3 are rotating around their common center of mass on elliptic orbits with hierarchical configuration M3 ≪ M2 ≪ M1. A new type of the solving procedure

Tuberculosis remains a major health challenge for the humans of the whole world, especially in developing countries including Pakistan. Despite being a preventable and curable disease, TB is still the world’s top infectious killer and among the leading diseases causing morbidity and mortality. In this paper, we formulate a deterministic model to study the dynamics and possible control of TB disease

Photon pairs produced in spontaneous parametric down-conversion are naturally entangled in their transverse spatial degrees of freedom including the orbital angular momentum. Pumping a nonlinear crystal with a zero-order Gaussian mode produces quantum correlated signal and idler photons with equal orbital angular momentum and opposite signs. Measurements performed on one of the photons prepares the

In this paper, we present a new approach to deterministic modelling of COVID-19 epidemic. Our model dynamics is expressed by a single prognostic variable which satisfies an integro-differential equation. All unknown parameters are described with a single, time-dependent variable R(t). We show that our model has similarities to classic compartmental models, such as SIR, and that the variable R(t) can

The principal aim of this paper is to analyse the two-dimensional magnetohydrodynamic flow and heat and mass transfer phenomena of water-based nanofluid containing gyrotactic microorganisms over a vertical plate by means of heat generation or absorption. Set of nonlinear ordinary differential equations are derived from the governing partial differential equations of the two-dimensional flow of MHD

Semiconductor nanowires with strong Rashba spin-orbit coupling are currently on the spotlight of several research fields such as spintronics, topological materials and quantum computation. While most theoretical models assume an infinitely long nanowire, in actual experimental setups the nanowire has a finite length, is contacted to metallic electrodes and is partly covered by gates. By taking these

We investigate the generation and propagation of solitary waves in the context of the Hertz chain and Toda lattice, with the aim to highlight the similarities, as well as differences between these systems. We begin by discussing the kinetic and potential energy of a solitary wave in these systems and show that under certain circumstances the kinetic and potential energy profiles in these systems (i

Abstract The titanium glycolate colloids nanoparticle [TiO2-EG]NP is synthesized at pH ≅ 7, using solgel polymerization mothed. The polymerization method is accomplished in ethylene glycol solution as a soft template at 298 K. The polymerization technique to the production of [TiO2-EG]NP. The resulting [TiO2-EG]NP are investigated by various methods involving FTIR and XRD. The thickness of fabricated

In this article, we demonstrate the weak gravitational lensing in the context of Bocharova–Bronnikov–Melnikov–Bekenstein (BBMB) black hole. To this desire, we derive the deflection angle of light in a plasma medium by BBMB black hole using the Gibbons and Werner method. First, we obtain the Gaussian optical curvature and implement the Gauss–Bonnet theorem to investigate the deflection angle for spherically

We theoretically investigate the coherent time of a single qubit in a RbCl quantum well (QW) with asymmetric Gaussian confinement potential (AGCP) using the Pekar-type variational method. Additionally, we utilize Fermi’s golden rule to consider strong coupling between electrons and longitudinal optical phonons in the QW with an electric field applied. The results show that the coherence time changes

In this paper, we propose a scheme for quantum information transfer by a gap-tunable bridge qubit between two superconducting (SC) qubits, which are initially prepared in separable quantum states. As is observed, enough high-fidelity and maximally entanglement between the two superconducting resonators, as well as between the two of qubits, can be achieved. It is shown that by implementing driven magnetic

In this paper, we formulate a mathematical model to investigate a within-host HIV dynamics under the effect of cytotoxic T lymphocytes immune response. The model incorporates two modes of transmission, virus-to-cell (VTC) and cell-to-cell (CTC). The CTC infection is due to the contact of healthy CD\(4^{+}\) T cells with (i) silent HIV-infected cells, and (ii) active HIV-infected cells. The model integrates

We derive a new hyperbolic model describing the propagation of internal waves in a stratified shallow water with a non-hydrostatic pressure distribution. The construction of the hyperbolic model is based on the use of additional instantaneous variables. This allows one to reduce the dispersive multi-layer Green–Naghdi model to a first-order system of evolution equations. The main attention is paid

Some years ago, Fotsin and Woafo (Phys Scrip 71:241, 2005) introduced and investigated an electronic circuit consisting of Van der Pol oscillator coupled to a linear oscillator, which appeared to be chaotic. Later, some few authors investigated chaos synchronization of this model. However, detail dynamical analyses and experimental verification of this interesting model were not carried out till now

The main target of this investigation is to propose an effective anodic electrocatalyst for micro-direct methanol fuel cell. For this purpose, five nanostructured metal alloy electrocatalysts including platinum (Pt), ruthenium (Ru) and iron (Fe) are synthesized. The single-walled and multi-walled carbon nanotubes (SW-CNT and MW-CNT) and graphene (Gr) are employed as the carbon (C) base. First, PtRuFe/SW-CNT

This work deals with the presence of thick branes in a model with two source scalar fields that interact with one another in a very specific way. The model is new, capable of generating kink-like configurations that engender important modifications in the energy density of the system, inducing the presence of symmetric and asymmetric structures inside the brane.

In this paper, we investigate the relativistic quantum dynamics of spin-0 massive charged particles in the presence of an external field in a Gödel-type space-time with potentials. We derive the radial wave equation of the Klein–Gordon equation with an external uniform magnetic field including a magnetic quantum flux subject to a Coulomb-type scalar and vector potentials in the background of the Som–Raychaudhuri

In this work, we present a new version of the Bohr collective Hamiltonian for triaxial nuclei within deformation-dependent mass formalism (DDM) using the Hulthén potential. We shall call the developed model Z(5)-HD. Analytical expressions for energy spectra are derived by means of the recent version of the asymptotic iteration method. The calculated numerical results of energies and B(E2) transition

In this paper, Lie-point symmetries and conservation laws for the generalized Grad–Shafranov equation (GGSE) for symmetric magnetohydrodynamic (MHD) fluids with steady, inhomogeneous, incompressible flows are derived. The adjointness of that equation is discussed via a Lie operator. We noted that the GGSE can be self-adjoint, quasi-self-adjoint or nonlinear self-adjoint according to a physical magnetic

We analyze the solution of the Schrödinger equation with a quark–antiquark potential obtained in a paper published recently in this journal. The authors derived their results in a rather arbitrary way from an ansatz that is not square integrable and used them to fit experimental data.

The cosmological candidate fields for dark energy as quintessence, phantom and cosmological constant are studied in terms of an entropic hypothesis imposed on the McVittie solution surrounded by dark energy. We certify this hypothesis as “D-bound-Bekenstein bound identification” for dilute systems and use it as a criterion to determine which candidate of dark energy can satisfy this criterion for a

Abstract This paper is concerned with the free vibration and transient response of graphene platelets reinforced functionally graded (GPL-FG) cylindrical shell resting on elastic foundation by utilizing the Chebyshev–Lagrangian approach. The boundary constraints are realized by setting reasonable values of stiffness of the artificial virtual springs. According to FSDT, the analysis model of GPL-FG

By using the formalism of thin-shells, we construct a geometrical model of a particle in third-order Lovelock gravity. This particular theory, which is valid at least in 7 dimensions, provides enough degrees of freedom and grounds towards such a construction. The particle consists of a flat interior and a non-black hole exterior spacetimes whose mass, charge and radius are determined from the junction

Generation of drift waves by field-aligned shear flow of protons and oxygen ions is investigated in the presence of kappa distributed trapped electrons in upper ionosphere within auroral latitudes. Very low-frequency electrostatic waves having frequencies of the order of a few Hz observed by Freja satellite at altitude 1700 km can be either the ion acoustic waves (IAWs) or the electrostatic drift waves

By introducing a memristor to the jerk system, a four-dimensional (4D) chaotic system is proposed. This system has five line equilibrium points with different stability. The extremely rich dynamic behaviors are studied by numerical simulation and theoretical analysis. Specifically, transient dynamics of coexisting chaotic attractors with different amplitudes at different time scales are found. And

The article presents modeling of inflationary scenarios for the first time in the f(R, T) theory of gravity. We assume the f(R, T) functional form to be \(R + \eta T\), where R denotes the Ricci scalar, T the trace of the energy-momentum tensor and \(\eta \) the model parameter (constant). We first investigated an inflationary scenario where the inflation is driven purely due to geometric effects outside

In the field of neutron scattering science, a large variety of instruments require detectors for thermal and cold neutrons. Helium-3 has been one of the main actors in thermal and cold neutron detection for many years. Nowadays, neutron facilities around the world are pushing their technologies to increase the available flux delivered at the instruments; this enables a completely new science landscape

The high wide-band-gap β-gallium oxide (β-Ga2O3) has attracted attention for high-voltage and high-speed applications over other wide-band-gap materials. In this work, we propose and demonstrate a β-Ga2O3 metal semiconductor field effect transistor (GO-MESFET) with an insulator layer (Si3N4) at the bottom of drift region (IL-GO-MESFET) to amend the potential and electric field distributions. In the

The nonlinear transmission line and the low-pass electrical transmission line equations are very important nonlinear evolution equations in electrical transmission line management. The modified simple equation (MSE) technique is a compatible and effective mathematical tool to extract soliton solutions of science and engineering problems. In this article, the MSE technique is introduced and implemented

This paper pays attention to the Cauchy problem for a class of nonlinear wave equations with linear pseudo-differential operator. In the framework of variational arguments, the existence and nonexistence of global solution to this problem are derived when the total initial energy is less than or equal to the mountain pass level. Further, a finite-time blowup result for arbitrarily high initial energy

This paper focus on seeking the N-soliton solutions for the matrix mKdV equation, which generalizes to the multi-component mKdV equations and the coupled mKdV equations. By utilizing the technique of Riemann–Hilbert and investigating the spectral problem of the Lax pair, a class of Riemann–Hilbert problem will be discussed and established. Finally, in the case of irregularity and reflectionless, we

The approximate solutions of Schrödinger equation for the Hua plus modified Eckart potential are obtained using the parametric Nikiforov–Uvarov method. By the use of a suitable approximation to deal with the centrifugal term, we obtained analytical expressions of the eigenvalues and corresponding wave functions. Numerical results of the energy eigenvalue are presented. Also, special cases of this potential

In this paper, a three-dimensional numerical analysis was employed to investigate the flow and thermal fields over a leading edge of AGTB-B1 high-pressure turbine blade. The effect of different parameters on the film cooling was studied. The computational methodology includes the use of a structured, non-uniform hexahedral grid consisting of the main flow channel, the coolant delivery tube and the

The principal component analysis of the West European wind power production is worked out and presented. The overall production in 15 countries in Western Europe is highly correlated and it is shown that the sum-production is dominated by a number of principal components far less than the number of countries. This manifests the correlation of wind power production in the larger area such as Western

Beamed propulsion of a light sail based on radiation pressure benefits from a passively self-stabilizing “beam riding” diffractive film. We describe the optomechanics of a rigid non-spinning light sail that mitigates catastrophic sail walk-off and tumbling by use of a flat axicon diffraction grating. A linear stability analysis and numerical integration of the coupled translational and rotational equations

We calculated the frequency-dependent dielectric response (electric susceptibility) of layered ferroelectric–dielectric junction, biased by the time-dependent harmonic voltage with single frequency \(\omega \). Working point is stabilized, by the charge boundary condition between the layers, in the region with negative electric capacitance. The static susceptibility \(\chi _0\) is negative and the

In this paper, the design of stochastic computational intelligent solver is presented for the solution of mathematical model representing the dynamics of mosquito dispersal in a heterogeneous environment by feedforward artificial neural networks (FFANNs) trained with genetic algorithms (GAs) aided with sequential quadratic programming (SQP), i.e., FFANN-GASQP. In the scheme FFANN-GASQP, the formulation

In this paper, it is targeted to present exact and approximate solutions to the motion of fired projectile in air subject to the Magnus effect. Closed-form solutions for the speed of the object are provided either when the quadratic drag force is negligible or when the quadratic Magnus force is negligible. An expression for the vertical distance of the projectile thrown from a fixed position is also

Single crystals of SnSe are grown by direct vapor transport technique. The elemental composition of as-grown crystals determined by dispersive X-ray energy analysis showed the crystals to be slightly selenium rich and tin deficient. The X-ray powder diffraction showed the crystal to possess orthorhombic unit cell structure. The lattice parameters are in good match with reported data. The surface micro-topography

Hirota’s bilinear method is used in this paper to obtain some breather wave and lumps solutions to the Caudrey–Dodd–Gibbon equation through the symbolic Mathematica 12 package. This equation is converted into its potential version and then the transformation of Cole–Hopf is implemented on the equation to produce its bilinear form. We then formally derive some novel solutions such as breather-wave,

An analytical consideration of a nonlocal nonlinear Schrödinger equation with distributed coefficients is presented. The analysis is twofold: first, exact solutions of the nonlocal equation with constant coefficients are found along with the appropriate conditions for their existence, and second, using a similarity transformation the distributed equation, i.e. the equations with varying coefficients

The hierarchies of multicomponent models of Manakov type are briefly outlined. Many of them have important applications n nonlinear optics. Next, we develop a method for calculating the spectral curves for the multiphase solutions of these equations. We discuss also other multicomponent generalization of Manakov system to which our method can be extended.