Oscillatory Behavior Research Articles

Raman-induced compound-mode squeezing in a nonlinear coupler implementing Wigner representation and the analytical method

We investigate the generation of compound-mode squeezing in a Raman nonlinear coupler using both the analytical perturbative (AP) method and the Wigner phase-space representation. While the AP approach is rooted in the Heisenberg picture, the Wigner representation employs the Schrödinger picture, enabling a detailed comparison of the two frameworks. The temporal evolution of compound-mode squeezing is rigorously analyzed across different mode combinations, revealing an oscillatory behavior within a specific time window that depends on key system parameters. The optimal point within this window offers insights into maximizing squeezing under precise conditions. Both methods yield consistent results, providing robust insights into the dynamics of squeezing. This study advances the understanding of compound-mode squeezing in Raman nonlinear systems, with unique applications in quantum metrology, secure quantum communication, and advanced quantum sensing technologies.

An amplification mechanism for weak ELF magnetic fields quantum-bio effects in cancer cells

Observing quantum mechanical characteristics in biological processes is a surprising and important discovery. One example, which is gaining more experimental evidence and practical applications, is the effect of weak magnetic fields with extremely low frequencies on cells, especially cancerous ones. In this study, we use a mathematical model of ROS dynamics in cancer cells to show how ROS oscillatory patterns can act as a resonator to amplify the small effects of the magnetic fields on the radical pair dynamics in mitochondrial Complex III. We suggest such a resonator can act in two modes for distinct states in cancer cells: (1) cells at the edge of mitochondrial oscillation and (2) cells with local oscillatory patches. When exposed to magnetic fields, the first group exhibits high-amplitude oscillations, while the second group synchronizes to reach a whole-cell oscillation. Both types of amplification are frequency-dependent in the range of hertz and sub-hertz. We use UV radiation as a positive control to observe the two states of cells in DU and HELA cell lines. Application of magnetic fields shows frequency-dependent results on both the ROS and mitochondrial potential which agree with the model for both type of cells. We also observe the oscillatory behavior in the time-lapse fluorescence microscopy for 0.02 and 0.04 Hz magnetic fields. Finally, we investigate the dependence of the results on the field strength and propose a quantum spin-forbidden mechanism for the effect of magnetic fields on superoxide production in QO site of mitochondrial Complex III.

Theoretical investigation of electronic structure and carrier mobility in boron antimonide nanotubes

Abstract High-mobility semiconductor nanotubes have demonstrated great potential for applications in high-speed transistors, single-charge detection, and memory devices. Here we systematically investigated the electronic properties of single-walled boron antimonide (BSb) nanotubes using first-principles calculations. We observed that rolling the hexagonal boron antimonide monolayer into armchair (ANT) and zigzag (ZNT) nanotubes induces compression and wrinkling effects, significantly modifying the band structures and carrier mobilities through band folding and π *-σ * hybridization. As the chiral index increases, the band gap and carrier mobility of ANTs decrease monotonically, where electron mobility consistently exceeds hole mobility. In contrast, ZNTs exhibit a more complex trend: the band gap first increases and then decreases, and the carrier mobility displays oscillatory behavior. In particular, both ANTs and ZNTs could exhibit significantly higher carrier mobility compared to hexagonal monolayer and zinc-blende BSb, reaching 103-107 cm2V-1s-1. Our findings highlight strong curvature-induced modifications in the electronic properties of single-walled BSb nanotubes, demonstrating the latter is a promising candidate for high-performance electronic devices.

Testing an oscillatory behavior of dark energy

The main aim of this work is to use a model-independent approach, along with late-time observational probes, to reconstruct the dark energy (DE) equation of state wDE(z). Our analysis showed that, for a late time universe, wDE deviates from being a constant but in contrast exhibits an oscillatory behavior, hence both quintessence (wDE>−1) and phantom (wDE<−1) regimes are equally allowed. In order to portray this oscillatory behavior, we explored various parametrizations for the equation of state and identified the closest approximation based on the goodness of fit with the data and the Bayesian evidence analysis. Our findings indicated that while all considered oscillating DE parametrizations provide a better fit to the data, when compared to the cosmological constant, they are penalized in the Bayesian evidence analysis due to the additional free parameters. Overall, the present article demonstrates that, in the low redshift regime, the equation of state of the DE prefers to be dynamical and oscillating. We anticipate that future cosmological probes will take a stand in this direction. Published by the American Physical Society 2025

On Complex Dynamics and the Schrodinger Equation

Complex Ginzburg-Landau equation (CGLE) is a paradigm of complex dynamics that holds for all spatially extended systems near the onset of oscillatory behavior. CGLE applies to a vast array of phenomena ranging from superconductivity and superfluidity, to Bose-Einstein condensation, astrophysics, nonlinear optics and spatiotemporal chaos. In particular, CGLE describes the formation of dissipative spacetime structures in Reaction-Diffusion (RD) processes. Here we bridge the gap between CGLE and the RD model of evolving dimensional fluctuations, the latter being conjectured to arise far above the electroweak scale. Our findings open an intriguing path connecting complex dynamics of dimensional fluctuations to Quantum Physics.

The effect of time delay on the dynamics of a fractional-order epidemic model

This study establishes a novel time-delay fractional SEIHR infectious disease model to investigate the effects of saturated incidence rates and time delays on different populations, including susceptibles, infected individuals, recovered individuals, and latent infected individuals. First, the existence and boundedness of the model’s solutions are verified, confirming its well-posedness. Subsequently, the existence of equilibria is analyzed, and the impact of parameter variations on the system is explored by examining the equilibria ϵ0 and ϵ∗, as well as the basic reproduction number R0. Additionally, the global dynamics of the equilibria are further analyzed using the Lyapunov method, while Hopf bifurcation theory is applied to explore the conditions under which the system shifts from stability to oscillatory behavior. Numerical simulations further validate the theoretical analysis, showing that time-delay effects significantly influence the system’s responsiveness and the rate of disease transmission. Moreover, when the time delay τ crosses the critical threshold τ0, the system exhibits periodic oscillations. By predicting periodic fluctuations and incorporating memory effects and persistent influences, we can better control epidemics, emphasizing the importance of time-delay adjustments and enhancing the system’s biological realism.

Investigation of magnetic fluctuations in L-H and H-L transition dynamics on DIII-D

Abstract The dynamics of the L-H transition is not fully understood, with many parameters changing the threshold power to enter H-mode and the self-regulation between zonal flows and turbulence in the plasma edge. This paper presents power threshold analysis for DIII-
D L-H and H-L transitions, as well as measurements of pedestal temperatures for these transitions. A comparison is made between an L-H transition and H-L transition of comparable Psep exhibiting oscillatory behaviour, showing symmetry between forward and backward transition dynamics. Information geometry analysis has been performed on measurements of plasma density fluctuations, perpendicular plasma velocity fluctuations, and magnetic field fluctuations to investigate the self-regulation of these variables during the transitions. Perpendicular flow evolution is shown to dominate the transition dynamics in both directions, but self-regulation behaviour is observed between all three variables. A strong correlation between magnetic fluctuation information rate and density fluctuation information rate for these two shots indicates the strong influence of magnetic behaviour on both the L-H and H-
L transition, and that these transition dynamics have an electromagnetic contribution. Some parameter dependencies of the magnetic fluctuation activity are presented.

Oscillatory nature in melt-gas-powder interactions during laser powder bed fusion process revealed by CFD-DEM coupled modelling

ABSTRACT The laser powder bed fusion (LPBF) process encompasses interactions between different material states, including melt, gas, and powder. While observational techniques can capture specific states, they cannot be combined to produce a comprehensive monitoring how they are mutually interacted. Thus, an integrated modelling approach is a crucial solution for revealing their interactions. This study investigates melt-gas-powder dynamics under varying laser scan speeds through a coupled CFD-DEM multiphase model. Findings reveal that metal vapour consistently transitions from an initialisation phase to a processing phase, exhibiting consistent behaviour in the former but varied responses in the latter. A relationship is identified between scan speed and vapour flow angle (VFA), with higher speeds broadening the VFA. Significantly, three oscillatory behaviours are observed: first, the oscillation of locally intensified pressure (LIP) sites on keyhole walls, where vapour ejection modes shift and may become periodic at intermediate scan speeds; second, the oscillation of two induced argon vortex flows with opposite swirling directions; and third, a simultaneously induced varying drag force on powder spatter. These oscillations clarify various spatter mechanisms, offer insights for process optimisation, and suggest implications for process stability. The study also proposes future research directions to further elucidate these mechanisms.

Investigating Oscillations in Higher-Order Half-Linear Dynamic Equations on Time Scales

This study presents novel and generalizable sufficient conditions for determining the oscillatory behavior of solutions to higher-order half-linear neutral delay dynamic equations on time scales. Utilizing the Riccati transformation technique in combination with Taylor monomials, we derive new and comprehensive oscillation criteria that cover a wide range of cases, including super-linear, half-linear, and sublinear equations. These results extend and improve upon existing oscillation criteria found in the literature by introducing more general conditions and providing a broader applicability to different types of dynamic equations. Furthermore, the study highlights the role of symmetry in the underlying equations, demonstrating how symmetry properties can be leveraged to simplify the analysis and provide additional insights into oscillatory behavior. To demonstrate the practical relevance of our findings, we include illustrative examples that show how these new criteria, along with symmetry-based perspectives, can be effectively applied to various time scales.

Connection between geometric dimension and dynamic response of bistable composite laminate with variable curvatures

Geometric dimension significantly affects the stable configuration and thereby the nonlinear dynamic response of bistable composite laminate. Previous studies have not focused on the minimum dynamic snap-through excitation of stable configuration transformation. This paper aims to address this gap by taking into account the effect of curvature on the bistable composite laminate with different geometric dimensions. The room-temperature equilibrium stable states of unsymmetric composite plates are obtained by cooling down from the cured temperature with variable curvatures. The governing equations are established by the first-order shear deformation theory, von Karman type nonlinear strain-displacement relation, and Rayleigh-Ritz method. The single- and double-well vibration mechanism are explored by solving the nonlinear equations via fourth-order Runge-Kutta method, and are visualized by bifurcation diagram, phase portrait, time history, Poincare maps and amplitude spectrum. The evolution of the dynamic response under the foundation excitation is estimated, and the effect of geometric dimension on the intra- and inter-well oscillation behaviors are illustrated in detail via theoretical model. Numerical results with finite element method are also obtained qualitatively consistent with the theoretical results. In view of the efficiency of the theoretical model, various geometric dimensions are considered to elucidate the universality of the vibration evolution. The nonlinear phenomenon that emerged in the dynamic response of composite structures provides a conceptual design of energy harvester and adaptive structure.

Kinetics and dynamics of atomic-layer dissolution on low-defect Ag.

Electrochemical metal dissolution reaction is a fundamental process in various critical technologies, including metal anode batteries and nanofabrication. However, experimentally revealing the kinetics and dynamics of active sites of metal dissolution reactions is challenging. Herein, we investigate metal dissolution on near-perfect single-crystal surfaces of Ag within regions of a few hundred nanometers isolated by scanning electrochemical cell microscopy (SECCM). Potential oscillation is observed under constant current conditions for dissolution. The one-to-one correspondence between the dissolution charge and the geometry of the dissolution pit from colocalized imaging allows ambiguous correlation, which suggests that each oscillation cycle corresponds to the dissolution of one atomic layer. The oscillation behavior is further explained in a kinetic model, which reveals that the oscillation comes from the dynamic evolution of the number of different active sites as the dissolution progresses on each atomic layer. In addition to the fundamental interest, the ability to observe layer-by-layer dissolution in electrochemical measurements suggests a potential pathway for developing electrochemical atomic layer etching for fabricating structures and devices with atomic precision.

Synchronization of a Kuramoto type model in a dynamic network

In this paper, we study the synchronization behavior of identical Kuramoto oscillators in a dynamic network. Our model is a variant of the classical Kuramoto model. Using the spectral gap of a connected stochastic matrix, we present a sufficient framework for synchronization in terms of initial data and model parameters. Moreover, we show that the system achieves a synchronous state at an exponential rate.

The stress bifurcation and large amplitude oscillatory shear behavior of Kamani–Donley–Rogers model

The stress bifurcation and large amplitude oscillatory shear behavior of Kamani–Donley–Rogers model

Remarks on a nonlinear electromagnetic extension in AdS Reissner-Nordström spacetime

We explore the gravitational properties of a nonlinear electromagnetic extension of an AdS Reissner-Nordström black hole. Our study begins with an analysis of the metric function and horizon structure, followed by calculations of the Ricci and Kretschmann scalars and an evaluation of the non-vanishing Christoffel symbols. These calculations allow us to examine geodesics and their influence on the photon sphere and shadow formation. In the thermodynamic framework, we evaluate essential quantities, including the Hawking temperature, entropy, heat capacity, Gibbs free energy, and Hawking radiation emission. We further investigate black hole evaporation by estimating the evaporation timescale as the black hole approaches its final state. Additionally, quasinormal modes for scalar and vector perturbations are computed using the WKB approximation to characterize oscillatory behavior of the system. Finally, a time-domain analysis is provided in order to examine the evolution of these perturbations.

Some new oscillation results for second-order differential equations with neutral term

<p>In this paper, we study the oscillatory behavior of second-order differential equations. Using the comparison method, we obtain new oscillation criteria that improve the relevant results in the literature. Additionally, an example is given to illustrate the importance of the obtained oscillation criteria.</p>

Distinct photon-ALP propagation modes

Measurement of cosmic photons may reveal their propagation in the interstellar environment, thereby offering a promising way to probe axions and axion-like particles (ALPs). Numerical methods are usually used to compute the propagation of the photon-ALP beam due to the complexity of both the interstellar magnetic field and the evolution equation. However, under certain conditions, the evolution equation can be greatly simplified so that the photon-ALP propagation can be analytically solved. By using analytic methods, we find two distinct photon-ALP propagation modes, determined by the relative magnitude of the photon-ALP mixing term in comparison to the photon attenuation term. In one mode, the intensity of photons decreases with the increasing distance; in the other mode, it also exhibits oscillatory behavior. To distinguish the two propagation modes, we compute the observable quantities such as the photon survival probability and the degree of polarization. We also determine through analytic methods the conditions under which maximum polarization can be observed and the corresponding upper bound of the survival probability.

Proteome analysis of the spontaneous oscillatory behavior in 1,3-propanediol production from glycerol by Clostridium butyricum

Proteome analysis of the spontaneous oscillatory behavior in 1,3-propanediol production from glycerol by Clostridium butyricum

FULLY ANALYTICAL SOLUTION FOR THE FIRST SPECTRAL MOMENT OF A FLUOROPHORE IN SOLUTION

One of the common methods for assessing the solvation dynamics of a fluorescent system in a polar medium is the analysis of the first spectral moment behavior. So there is a need to build a model that takes into account important physical processes and at the same time is not demanding in terms of calculations. In this paper, an approach is proposed that considers the parameters of the exciting laser pulse and intramolecular vibrational relaxation for constructing the solvation dynamics. A method for building an analytical solution for the dynamics of the first spectral moment is presented. This model is free of numerical methods using, and it is a simple construction built by basics functions and an additional error function. The influence of all key parameters on the system relaxation is illustrated. It is shown that delocalization in time of the pump pulse suppresses the oscillatory behavior of the first moment and hides information about the damped intramolecular mode. The similar effect is also observed with the diffusion and inertial processes contribution insreasion to the reorganization energy at early stages of relaxation. The presented model can be generalized to take into account quantum transitions between vibrational sublevels of high-frequency intramolecular vibrations.

Oscillatory autophagy induction is enabled by an updated AMPK-ULK1 regulatory wiring.

Autophagy-dependent survival relies on a crucial oscillatory response during cellular stress. Although oscillatory behaviour is typically associated with processes like the cell cycle or circadian rhythm, emerging experimental and theoretical evidence suggests that such periodic dynamics may explain conflicting experimental results in autophagy research. In this study, we demonstrate that oscillatory behaviour in the regulation of the non-selective, stress-induced macroautophagy arises from a series of interlinked negative and positive feedback loops within the mTORC1-AMPK-ULK1 regulatory triangle. While many of these interactions have been known for decades, recent discoveries have revealed how mTORC1, AMPK, and ULK1 are truly interconnected. Although these new findings initially appeared contradictory to established models, additional experiments and our systems biology analysis clarify the updated regulatory structure. Through computational modelling of the autophagy oscillatory response, we show how this regulatory network governs autophagy induction. Our results not only reconcile previous conflicting experimental observations but also offer insights for refining autophagy regulation and advancing understanding of its mechanisms of action.

Strong-field QED effects on polarization states in dipole and quadrudipole pulsar emissions

Highly magnetized neutron stars have quantum refraction effects on pulsar emission due to the non-linearity of the quantum electrodynamics (QED) action. In this paper, we investigate the evolution of the polarization states of pulsar emission under the quantum refraction effects, combined with the dependence on the emission frequency, for dipole and quadrudipole pulsar models; we solve a system of evolution equations of the Stokes vector, where the birefringent vector, in which such effects are encoded, acts on the Stokes vector. At a fixed emission frequency, depending on the magnitude of the birefringent vector, dominated mostly by the magnetic field strength, the evolution of the Stokes vector largely exhibits three different patterns: (i) monotonic, or (ii) half-oscillatory, or (iii) highly oscillatory behaviors. These features are understood and confirmed by means of approximate analytical solutions to the evolution equations. Also, the evolution patterns are shown to differ between dipole and quadrudipole pulsar models, depending on the magnetic field strength.