Reactivity is an important feature of every stable state to measure the short-term instability of such stable state in prey–predator models. Asymptotic stability is not a powerful tool to study the dynamics immediately after an equilibrium has disturbed. We are interested in studying the effect of disturbance made by harvesting effort to the stable state of a set of prey–predator models. We consider

Third-generation gravitational wave observatories will extend the lower frequency limit of the observation band toward 2 Hz, where new sources of gravitational waves, in particular intermediate-mass black holes (IMBH), will be detected. In this frequency region, seismic noise will play an important role, mainly through the so-called Newtonian noise, i.e., the gravity-mediated coupling between ground

After a short review of past and present EU green energy programmes, the article deals with the great surging interest on green hydrogen worldwide and the consequent programme of the EU. Considering the trend in the increasing percentage of variable wind and solar plants in the EU, a preliminary evidence on their variability is reported and based on their capacity factors during the different months

Angular deviations and lateral displacements are optical effects widely investigated in the literature. In this paper, by using the Taylor expansion of the Fresnel coefficients, we obtain an analytic expression for the beam reflected by and (upper) transmitted through a dielectric prism. These analytical approximations lead to a cubic equation which allows to determine the angular deviations of the

The present paper is devoted to study the spherically symmetric compact star model with anisotropic matter distribution in the framework of f(T) modified gravity. In this work, we choose off-diagonal tetrad along with the power law modal of f(T), where T is the torsion scalar. For the sake of simplicity in calculations, we use Karmarkar condition and develop a significant differential equation providing

This paper investigates static wormhole solutions through Noether symmetry approach in the context of energy–momentum squared gravity. This newly developed proposal resolves the singularity of big bang and yields feasible cosmological results in the early times. We consider the particular model of this theory to establish symmetry generators and corresponding conserved quantities. For constant and

In this paper, the definition of fractional calculus introduces a newly constructed discrete chaotic map. Interestingly, when the order is extended to the improper fractional order, the map still shows a chaotic state with appropriate parameters. The related dynamical behavior is analyzed by a phase diagram, bifurcation model, maximum Lyapunov exponent diagram, and approximate entropy algorithm method

Cultural heritage built from limestone is prone to deterioration by chemical weathering, a natural process, that is enhanced by pollution. There are many historic monuments built from calcareous rocks that suffer from deterioration, and thus there have been a number of approaches over the last few decades to consolidate these types of rocks and surfaces. Using natural biological processes by fostering

In this work we describe semiclassical states in graphene under a constant perpendicular magnetic field by constructing coherent states in the Barut–Girardello sense. Since we want to keep track of the angular momentum, the use of the symmetric gauge and polar coordinates seemed the most logical choice. Different classes of coherent states are obtained by means of the underlying algebra system, which

Starting with an N body system describing a Bose gas at finite temperatures, we derive a new model that contains a Gross–Pitaevskii equation of motion for the condensate wave function and a quantum Boltzmann equation for the excitations. The model is valid for a wide range of finite temperatures and approaches the standard ZNG model when the temperature of the system T is close to the Bose–Einstein

After the discovery of the Higgs boson in 2012, several future circular colliders — Higgs factories — are proposed, such as FCC-ee and CEPC. At these e\(^+\)e\(^-\) colliders, beamstrahlung can greatly affect the equilibrium bunch length and energy spread. If the dispersion function at the collision point is not zero, beamstrahlung will also increase the transverse emittances. In this paper, we derive

In this paper, double-diffusion natural convection for staggered cavities with a concaved lower wall is investigated. The finite volume procedure is utilized to solve the governing equations along with the boundary conditions. The current code is validated with previously published results. Impacts of Rayleigh number (104 ≤ Ra ≤ 106), buoyancy ratio (− 5 ≤ N ≤ 5), Lewis number (1 ≤ Le ≤ 5), and aspect

Near-infrared spectroscopy (fNIRS) measures concentrations of oxygenated (HbO) and deoxygenated (HbR) hemoglobin in the brain. Recently, we demonstrated its potential also for measuring concentrations of cerebral water (\(\hbox {cH}_{2}\hbox {O}\)). We performed fNIRS measurements during rest to study fluctuations in concentrations of \(\hbox {cH}_{2}\hbox {O}\), HbO and HbR in 33 well-rested healthy

Eukaryotic cells adhere to extracellular matrix during the normal development of the organism, forming static adhesion as well as during cell motility. We study this process by considering a simplified coarse-grained model of a vesicle that has uniform adhesion energy with a flat substrate, mobile-curved membrane proteins and active forces. We find that a high concentration of curved proteins alone

We investigate the planar nonlinear quantum dynamics of a self-interacting electron in the presence of an external homogeneous magnetic field in \(3+1\) flat space-time dimensions. In cylindrical coordinates, nonlinearities are introduced via the Nambu–Jona-Lasinio interaction. Special attention is given to the strong-field QED regime. We obtain the approximate (nonlinear) ground-state Landau energy

In this paper, the heat transfer characteristics associated with the impact of combined electromagnetohydrodynamic flow in a microchannel with the regular wavy rough wall through a porous medium have been investigated. The approximate analytical solutions for the velocity and potential distribution are obtained using the perturbation technique. To study the thermal characteristics, the analytical solution

Under the influence of peristaltic propulsion and an induced magnetic field, this article investigates the impact of double-diffusivity convection on Powell–Eyring nanofluids in a non-uniform channel. Firstly, Powell–Eyring nanofluids with induced magnetic field and double-diffusivity convection are mathematically modelled. We apply the principle of long wavelength and approximation of low but finite

We find real spectral behaviour in negative potentials having PT-symmetry in nature. Apart from linear non-polynomial and polynomial operators, we also consider few nonlinear quantum operators. In the case of polynomial operators, we use appropriate supersymmetry Hamiltonians and verify the iso-spectral nature of energy eigenvalues. All the quantum operators are one-dimensional in nature. The present

We investigate two-dimensional anisotropic spin-\(\frac{1}{2}\) lattice for XXZ model using concurrence and quantum Fisher information. The model is solved by using quantum renormalization group method and observed the quantum phase transition in thermodynamic limit. After sufficient iterations of quantum renormalization group, the concurrence and quantum Fisher information both attain two different

This paper studies mechanisms of synchronisation and loss of synchrony among the three key oscillatory processes controlling sleep–wake cycles in the human brain: the 24-h circadian oscillator, the homeostatic sleep drive, and the environmental light–dark cycle. Synchronisation of these three rhythms promotes sleep and brain clearance and is critical for human health. Their desynchrony, on the other

This paper represents a three-dimensional numerical simulation to figure out the application of the DBD plasma actuators as an active vortex generator system to enhance heat transfer through a smooth rectangular channel. This system as an active flow control device consists of a pair of DBD plasma actuators, which have been implemented asymmetrically on the bottom wall by several angles of attack to

In a nuclear or radiological accident scenario, where members of the public can potentially take up anthropogenic radionuclides released in atmosphere, verified methods to fast screen for internal contamination a large number of individuals directly on the field can play a major role to adopt appropriate countermeasures. At the ENEA Casaccia Research Centre (Rome, Italy), a spectrometric monitoring

In this paper, we study the geodesic motion in the spacetime of a SU(2)-colored (A)dS black hole in conformal gravity, and also we investigate spacetime features, such as light spheres and horizons. Moreover, we derive the analytical solutions for the equation of motion of test particles and light rays using Weierstrass elliptic and Kleinian \(\sigma \) functions. Depending on the particle energy levels

Light sail acceleration by ultrashort, superintense laser pulses is presently investigated as an approach to compact accelerators of matter. The usual light sail equation assumes a cycle-averaged light pressure, which becomes questionable for ultrashort pulse drivers or in the highly relativistic regime. Here, we remove such assumption and compute solutions of the light sail equations which show oscillations

This work deals with the development of an efficient interpolating wavelet collocation scheme for obtaining highly accurate eigenstates of Sturm–Liouville problem with a view to divulge some hidden bound state spectrum of quasi-exactly solvable models in non-relativistic quantum mechanics in \(\mathbb {R}\). The properties of scale functions in the interpolating wavelet basis generated by scale function

This paper presents a scheme for strong self-focusing of a laser beam interacting with a cone-guided fast-ignition inertial confinement fusion target using cone pre-plasma filling as an optical medium for reducing the laser beam waist. The objective is to reduce the focal spot size at the interior of the tip of the re-entrant cone to that required for efficient coupling to the dense imploded fuel core

We propose a model, which describes the transfer of a marker inside the lymphatic microvessel by the lymph flow as a consequence of the vessel’s elastic deformation, which produces the pushing pressure jump. The resulting model is close to the equation of the nonlinear diffusion with a localized moving front solution. The simulations are compared with the processed data of experimental recordings of

Ionizing radiation is ubiquitous in the environment. Its source can be natural, such as radioactive materials present in soil and cosmic rays, or artificial, such as the fuel for nuclear power plants. Overexposure to ionizing radiation may damage living tissue and could cause severe health problems (i.e., mutations, radiation sickness, cancer, and death). Cytogenetic bio-dosimetry has the great advantage

In a recent work, we introduced a novel method to compute the effective reproduction number \(R_t\) and we applied it to describe the development of the COVID-19 outbreak in Italy. The study is based on the number of daily positive swabs as reported by the Italian Dipartimento di Protezione Civile. Recently, the Italian Istituto Superiore di Sanità made available the data relative of the symptomatic

A variety of physical mechanisms acting over a long horizontal cylinder is studied in the present paper. The devotion is to discover some further exact solutions representing the flow and heat under new mechanisms. These include the wall slippage, temperature jump, free convection and asymptotic suction. The expansion or contraction of the cylinder implying that the radius is also changing in time

We study the linear response of the deformation potential of a chiral two-orbital superconductor Sr\(_2\)RuO\(_4\) to the applied strain. This response rises due to the strain-induced modified interatomic distances. In the linear response theory, the deformation potential–deformation potential correlation function defines the full complex frequency-dependent viscosity tensor. We calculate the anti-symmetric

In this paper, we find the minimal number of correlation tests required to certify independence of two classical random variables of arbitrary finite support. Moreover, we completely characterize the constraints implied by zero correlations upon an arbitrary heterogeneous quantum state, and we solve the conjecture proposed by Ohira in 2020. Finally, we find the first ever algorithm for computing (or

The similarity solutions using Lie group analysis for shock wave propagation in a rotational axisymmetric non-ideal gas with azimuthal or axial magnetic field in the case of isothermal and adiabatic flows are obtained. All possible cases of similarity solutions are discussed using the Lie group analysis for the isothermal and adiabatic flows. The arbitrary constants involved in the generators of local

In this manuscript, we investigate the fear effect on the spatiotemporal behavior of the predator–prey model with prey social behavior and cross-diffusive. Our main interest is to determine the existence of Turing patterns and the fear effect performed by predators on the prey population and the group defense. The fear can lead to a partition of the prey herd which is known as prey escaping. It is

In this paper the Feynman Green function for Maxwell’s theory in curved space-time is studied by using the Fock–Schwinger–DeWitt asymptotic expansion; the point-splitting method is then applied, since it is a valuable tool for regularizing divergent observables. Among these, the stress-energy tensor is expressed in terms of second covariant derivatives of the Hadamard Green function, which is also

We investigate the correlation dynamics of a non-interacting two-qubit system which is embedded in a qutrit environment with a constant magnetic field. Two archetypal states, mainly a Bell state and a coherent state, are considered as the initial state, and their correlation dynamics are studied in the presence of the mentioned environment. It is shown that the concurrence, a measure of entanglement

The LABEC laboratory, the INFN ion beam laboratory of nuclear techniques for environment and cultural heritage, located in the Scientific and Technological Campus of the University of Florence in Sesto Fiorentino, started its operational activities in 2004, after INFN decided in 2001 to provide our applied nuclear physics group with a large laboratory dedicated to applications of accelerator-related

Charged particle multiplicity fluctuations in simulated pp collisions at \(\sqrt s = 13\;{\text{TeV}}\) have been studied by the method of scaled factorial moment for the minimum bias events generated by Ultra-Relativistic Quantum Molecular Dynamics (UrQMD) model in the pseudo-rapidity \((\eta )\), azimuthal angle (\(\phi\)) and two-dimensional anisotropic \((\eta - \phi )\) phase space. Strong intermittent

The critical worldwide revolution towards clean energy has prompted the improvement of studies on the fabrication of high-performance solar cells. In this regard, rendering an accurate model of the solar cell for performance evaluation in the simulation could be essential. So far, several models have been proposed for the solar cell, including single-diode model (SDM), double-diode model (DDM), and

Glasses with composition of (60 − x) TeO2 − 10SrO − (30 + x) B2O3 were fabricated by melt quenching method. The structural features have been studied using X-ray diffraction (XRD) and FTIR. The derivative of absorption spectra fitting (DASF) method has been utilized to determine the optical band-gap energy. The measured band-gap energies takes values 3.521, 3.558, 3.581, 3.620 and 3.669 eV for the

Recently, super-Chandrasekhar mass limit has been derived theoretically in the presence of strong magnetic field to complement experimental observations. In the framework of Newtonian physics, we have studied the equilibrium configurations of such magnetized white dwarfs by using the relativistic Thomas–Fermi equation of state for magnetized white dwarfs. Hartle formalism, for slowly rotating stars

The Chern–Weil topological theory is applied to a classical formulation of general relativity in four-dimensional spacetime. Einstein–Hilbert gravitational action is shown to be invariant with respect to a novel translation (co-translation) operator up to the total derivative; thus, a topological invariant of a second Chern class exists owing to Chern–Weil theory. Using topological insight, fundamental

An analytical and numerical study for the creeping flow caused by a solid spherical particle with a slip-flow surface is considered in the presence of a fluid–fluid plane interface. The particle rotating about or translating along an axis perpendicular to the interface. The motion is investigated in the limit of low capillary number where in this situation the interface is of negligible deformation

In this paper, we investigate a semi-discrete two-component integrable system on zigzag-runged ladder lattice and find a variety of two-component localized waves. First of all, we investigate the modulational instability to reveal the formation mechanism of rogue waves from three distinct plane-wave solutions for this system. Secondly, the discrete generalized \((m,N-m)\)-fold Darboux transformation

Any quantum state of a bosonic field can be described by a density operator on the system Hilbert space, or equivalently, by the corresponding Husimi function on the phase space. For the density operator, there is a family of quantum Tsallis entropies (including the von Neumann entropy as a particular instance) quantifying its uncertainty (mixedness), and for the Husimi function, there is a corresponding

In this paper, we obtain two types of semi-rational solutions for a coupled nonlinear Schrödinger equation by applying generalized Darboux transformation (DT). Firstly, we obtain a new DT through a special limit process based on the traditional DT for the equation; then, some nonlinear wave interactions on the zero-intensity background are analyzed under the research of those semi-rational solutions

This article makes the connection between the new gravitoelectromagnetic theory presented in the part I paper and general gravity in its weak formulation. The perturbation in the metric tensor is obtained in terms of the flat-space total energy–momentum tensor given by the sum of the consistent fully relativistic fluid and gravitoelectromagnetic field contributions. Expressions for the perturbed metric

In this paper, we have investigated the non-adiabatic spherical gravitational collapse in the framework of the f(R, T) theory of gravity with a locally anisotropic fluid that undergoes dissipation in the form of heat flux, free-streaming radiation, and shearing viscosity. The dynamical equations are analyzed in detail, both in the Newtonian and post-Newtonian regimes. Finally, we couple the dynamical

This paper employs the new robust solver to retrieve exact solutions to a Kaup–Newell model equation and the nonlinear coupled Konno–Oono equation. This solver yields the closed formula for the solutions. Different types of travelling wave solutions, i.e., rational function, hyperbolic function and trigonometric function solutions with many capricious parameters are revealed. Subsequently, by utilizing

We study the effect of orbital angular momentum transfer between optical fields in a semiconductor quantum well waveguide with four energy levels in a closed-loop configuration via four-wave mixing. The waveguide is driven by two strong control fields and two weak probe fields. We consider three different cases for the light-matter interaction in order to efficiently exchange optical vortices. In the

In this study, the dynamic behavior of composite beams reinforced by carbon nanotubes (CNTs) exposed to a mass moving is investigated. By considering the external potential energy due to the applied moving mass, the equations of motion of the CNT-reinforced beam are obtained using Hamilton’s principle by combining Reddy’s third-order shear deformation theory and nonlocal strain gradient theory. Three

The dynamics of accretion disk is considered taking into account the Lense–Thirring precession in the presence of cosmological constant \(\varLambda \) of Schwarzschild–de Sitter metric. The nodal and apsidal frequencies are obtained, and the role of \(\varLambda \) is revealed in their properties, including the consequences for the Bardeen–Petterson effect.

Investigations are done on the technique of solving an ill-posed and under-determined problem of unfolding (de-convoluting) neutron energy distributions from measured prompt gamma intensities. The prompt gammas originate from a combined system of high-density polyethylene (HDPE), borated HDPE with lead cover, and are detected by a NaI(Tl) gamma detector. The technique comprises of finding an average