Time Evolution Research Articles

Time evolution of the chaos intensity of cryptocurrencies

Time evolution of the chaos intensity of cryptocurrencies

Modulational instability for a cubic-quintic model of coupled Gross-Pitaevskii equations with residual nonlinearities

Abstract We demonstrate the existence of modulational instability (MI) in both trapped miscible and immiscible two component Bose-Einstein condensates. The study is addressed theoretically and numerically in the framework of one-dimensional coupled Gross-Pitaevskii equations incorporating intra- and interspecies cubic-quintic nonlinearities with higher order ones. Using the time-dependent variational approach, we derive the new Euler-Langrange equations for the time evolution of the phase and amplitude of the modulational perturbation as well as the effective potential and the instability criteria of the system. We examine the effects of higher-order nonlinearities on the instability dynamics of the condensates. We show that the modulational properties of the chosen wave numbers are significantly modified. Direct numerical simulations run by the split step Fourier method confirm the analytical predictions.

Performance and scaling analysis of variational quantum simulation

Abstract We present an empirical analysis of the scaling of the minimal quantum circuit depth required for a variational quantum simulation (VQS) method to obtain a solution to the time evolution of a quantum system within a predefined error tolerance. In a comparison against a non-variational method based on Trotterized time evolution, we observe a better scaling of the depth requirements using the VQS approach with respect to both the size of the system and the simulated time. Results are also put into perspective by discussing the corresponding classical complexity required for VQS. Our results allow us to identify a possible advantage region for VQS over Trotterization.

Quantum correlations and parameter estimation for two superconducting qubits interacting with a quantized field

In the present manuscript, we introduce a quantum system of two superconducting qubits (S–Qs) interacting with a quantized field under the influence of the Kerr nonlinear medium and Ising interaction. We formulate the Hamiltonian of the quantum model and determine the density operator of whole quantum system as well as quantum subsystems. We examine the dynamics of the quantumness measures for subsequent times including the S–Qs entanglement, S–Qs-field entanglement and quantum Fisher information in relation to the system parameters. Finally, we display the connection among the measures of quantumness during the time evolution.

Extremophiles and Extremophilic Behaviour—New Insights and Perspectives

Extremophiles, throughout evolutionary time, have evolved a plethora of unique strategies to overcome hardships associated with the environments they are found in. Modifying their genome, showing a bias towards certain amino acids, redesigning their proteins, and enhancing their membranes and other organelles with specialised chemical compounds are only some of those strategies. Scientists can utilise such attributes of theirs for a plethora of biotechnological and astrobiological applications. Moreover, the rigorous study of such microorganisms regarding their evolution and ecological niche can offer deep insight into science’s most paramount inquiries such as how life originated on Earth and whether we are alone in the universe. The intensification of studies involving extremophiles in the future can prove to be highly beneficial for humanity, even potentially ameliorating modern problems such as those related to climate change while also expanding our knowledge about the complex biochemical reactions that ultimately resulted in life as we know it today.

Time-dependent full-radius integrated modeling of the DTT tokamak main plasma scenarios

Abstract We use an integrated modeling workflow with the transport code ASTRA coupled with the quasi-linear transport model TGLF-SAT2, the neoclassical model NCLASS, the FACIT model for the neoclassical impurity transport and the IMEP routines for the pedestal calculations, in order to predict the evolution of the plasma profiles for the DTT tokamak main scenarios. The simulations cover the whole confined plasma radius, up to the separatrix, and the time evolution of the plasma including the early phase in limiter configuration, the whole current ramp-up phase in L-mode divertor configuration, the L-H transition and part of the stationary H-mode phase. Six fields are predicted, i.e. the ion and electron temperatures, the electron density, two impurity densities and the plasma current. The simulations indicate that the main DTT scenarios are within the technical capabilities of the machine. They also indicate that the DTT full power, full current, full field scenario will be able to operate in H-mode with a duration of the flat-top phase of the order of \sim30 seconds, and plasma parameters allowing a core-edge integrated study of the power exhaust, which is the main mission of the device. The simulations show also a strong flexibility of the DTT plasmas, that allows DTT to study reactor-relevant conditions unexplored by existing tokamaks.

Boosted imaginary time evolution of matrix product states

In this work, we consider the imaginary time evolution of matrix product states. We present a quantum-inspired classical method that, when combined with time evolving block decimation (TEBD), is able to potentially speed up the convergence to a ground state compared to TEBD alone. Our method, referred to as boosted imaginary time evolution, relies on the use of reflections to boost to lower energy states. Interleaving TEBD steps with boosts reduces the total number of TEBD steps and potentially the computational cost required to imaginary time evolve a matrix product state to a ground state. We give the mathematical details of the method followed by an algorithmic implementation and finally some results for a simple test case. Published by the American Physical Society 2024

On Some Dynamics in Conceptual Spaces

AbstractIn this text, we consider Gärdenfors’ conceptual spaces that are separable Hilbert spaces. In particular, the results we obtained apply to finite-dimensional Euclidean spaces. Our main contribution can be formulated as a combination of the theory of opinion dynamics with the theory of conceptual spaces. This combination, in turn, leads us to propose a new model for the time evolution of conceptual spaces. To achieve this goal, we propose some extension of the multidimensional opinion dynamics model of Parsegov, Proskurnikov, Tempo and Friedkin to opinions with values in Hilbert spaces.

The curious case of 2MASS J15594729+4403595, an ultra-fast M2 dwarf with possible Rieger cycles

Context. RACE-OC (Rotation and ACtivity Evolution in Open Clusters) is a project aimed at characterising the rotational and magnetic activity properties of the late-type members of open clusters, stellar associations, and moving groups of different ages. The evolution in time of rotation and activity at different masses sheds light on the evolution of the stellar internal structure, on magneto-hydrodynamic processes operating in the stellar interior, and on the coupling and decoupling mechanisms between the radiative core and the external convective envelope. As part of this project, in the present paper we present the results of an investigation of a likely member of the AB Doradus association, the M-type star 2MASS J15594729+4403595. Aims. In the present study, we aim to reveal the real nature of our target, which turned out to be a hierarchical triple system, to derive the stellar rotation period and surface differential rotation, and to characterise its photospheric magnetic activity. Methods. We have collected radial velocity and photometric time series, complemented with archive data, to determine the orbital parameters and the rotation period and we have used the spot modelling technique to explore what causes its photometric variability. Results. We found 2MASS J15594729+4403595 to be a hierarchical triple system consisting of a dwarf, SB1 M2, and a companion, M8. The M2 star has a rotation period of P = 0.37 d, making it the fastest among M-type members of AB Dor. The most relevant result is the detection of a periodic variation in the spotted area on opposite stellar hemispheres, which resembles a sort of Rossby wave or Rieger-like cycles on an extremely short timescale. Another interesting result is the occurrence of a highly significant photometric periodicity, P = 0.443 d, which may be related to the stellar rotation in terms of either a Rossby wave or surface differential rotation. Conclusions. 2MASS J15594729+4403595 may be the prototype of a new class of extremely fast rotating stars exibiting short Rieger-like cycles. We shall further explore what may drive these short-duration cycles and we shall also search for similar stars to allow for a statistical analysis.

Factors associated with Glycemia Risk Index in a cohort of patients with type 1 Diabetes Mellitus and Latent Autoimmune Diabetes In Adults (LADA).

To analyze the degree of control based on classical glucometric parameters and Glycemia Risk Index (GRI) in real-life conditions in a cohort of patients with type 1 Diabetes Mellitus (DM) and Latent Autoimmune Diabetes in Adults (LADA) and to assess the factors that are associated with GRI. Cross-sectional study. 447 adult patients with type 1 DM and LADA users of Intermittent Continuous Glucose Monitoring (iCGM) with an adherence ≥ 70% were included. GRI was calculated with its Hypoglycemia (CHypo) and Hyperglycemia (CHyper) Components. Multivariate linear regression analysis was performed to evaluate the factors associated with GRI. Mean age 44.6 years (SD 13.7); 57.7% men; 83.9% type 1 DM; 16.1% LADA; time of evolution 20.6 years (SD 12.3). In patients with type 1 DM vs. LADA, differences were observed in relation to age [-11.1 years (SD 1.7)], age of onset [-21.9 years (DE 1.5)], time of evolution [11.7 years (DE 1.5)], treatment modality (p < 0.001), Time in Range (TIR) [-6.3% (SD 2.2)], Time Below Range (TBR) [1.9% (SD 0.6)], TBR level 1 (TBR1) [1.4% (SD 0.5)], Time Above Range (TAR) level 2 (TAR2) [4.7% (SD 1.3)], Coefficient of Variation (CV) [4.6% (SD 0.9)], GRI [11.3% (SD 2.8)], CHypo [1.3% (SD 0.5)] and CHyper [4.8% (SD 1.7)]. The variables that were independently associated with GRI were TIR (β = -1.34; CI 95% -1.43 to -1.25; p < 0.001), Glucose Management Indicator (GMI) (β = -5.82; CI 95% -7.59 to -4.05; p < 0.001), CV (β = 0.67; CI 95% 0.57 to 0.77; p < 0.001) and adherence to sensor usage (β = -0.16; CI 95% -1.27 to -0.06; p < 0.002). LADA present better control according to some glucometric parameters and a low GRI. However, the type of DM is not a factor that is independently associated with GRI.

Simulation of a Mesoscale Convective System Using a New Formulation for Advection in a Bin Microphysics: Sensitivity to Advection, Microphysics, and Grid Spacing

Abstract A computationally efficient semi-Lagrangian advection (SLA) scheme designed for microphysical variable advection was implemented into the Weather Research and Forecasting (WRF) Model with spectral bin microphysics (SBM). The primary goal was to reduce the CPU time for advection of the scalar SBM variables and demonstrate its applicability to simulation of a real-data case study in the eta vertical coordinate system. A mesoscale convective system (MCS) in Midlatitude Continental Convective Clouds Experiment (MC3E-0520) was selected for simulations. We compared the SLA and high-order, nonlinear monotonic advection schemes and tested the sensitivity of the simulated radar reflectivity, microphysical, and dynamic properties of the MCS to the choice of microphysical schemes, aerosol concentration, and grid spacing. Simulations using the SLA and monotonic advection schemes were similar, and the differences between them were much smaller than those between the SBM and bulk microphysical schemes tested. Improvement of the grid resolution had a larger impact on the vertical velocity field than did the choice of aerosol concentration. The total computational time in simulations with SLA was about 25% shorter than that with monotonic advection, which resulted from a reduction of more than 50% in computational time required for advection of the microphysical variables. Significance Statement Clouds comprise particles of various sizes and types: aerosols, liquid droplets, ice crystals, hail, and snow. Two major approaches describe the time and spatial evolution of these particle species: solving basic microphysical (bin microphysics) and simplified parameterization (bulk microphysics) equations. Bin microphysics is time-consuming as it operates with size distributions described by multiple mass bins. Among the microphysical processes, the advection of the microphysical variables requires significant CPU time. We tested a new numerical advection scheme that requires several times less computer time than the standard high-order nonlinear schemes being of similar accuracy. Due to the introduced change, the advection of droplet size distributions became less of a factor affecting the total computer time of bin-type schemes. This is an important step toward making the bin approach computationally efficient without losing accuracy. It is shown that the sensitivity of the results to spatial grid spacing and to the choice of microphysical schemes is significant and may be larger than that to variations in the aerosol concentration.

Comprehensive Phylogenomic Analysis of Zika Virus: Insights into Its Origin, Past Evolutionary Dynamics, and Global Spread

BackgroundZika virus (ZIKV), a Flaviviridae family member, has been linked to severe neurological disorders. Despite detailed studies on recent outbreaks, the early evolutionary history of ZIKV remains partially unclear. This study elucidates ZIKV origin and evolutionary dynamics, focusing on recombination events, early lineage diversification, and virus spread across continents. MethodsWe assessed recombination using multiple methods. We conducted Bayesian phylogenetic analyses to understand the evolutionary relationships and timing of key diversification events. Model selection was carried out to determine the most appropriate evolutionary model for our dataset. ResultsOur phylogenies revealed recent recombination between Singaporean and African lineages, indicating the co-circulation of diverse lineages during outbreaks. Thailand was identified as a crucial hub in the spread across Asia. The phylogenetic analysis suggests that the ZIKV lineage dates back to the eleventh century, with the first significant diversification occurring in the nineteenth century. The timing of the re-introduction of the Asian lineage into Africa and the delay between probable introduction and outbreak onset were also determined. ConclusionsThis study provides novel insights into ZIKV's origin and early evolutionary dynamics, highlighting Thailand's role in the spread of the virus in Asia and recent recombination events between distant lineages. These findings emphasize the need for continuous surveillance and a better understanding of ZIKV biology to forecast and mitigate future outbreaks.

Dust ring and gap formation by gas flow induced by low-mass planets embedded in protoplanetary disks. II. Time-dependent model

The observed dust rings and gaps in protoplanetary disks could be imprints of forming planets. Even low-mass planets in the 1--10 Earth-mass regime, which have not yet carved deep gas gaps, can generate such dust rings and gaps by driving a radially-outward gas flow, as shown in previous work. However, understanding the creation and evolution of these dust structures is challenging due to dust drift and diffusion, requiring an approach beyond previous steady state models. Here we investigate the time evolution of the dust surface density influenced by the planet-induced gas flow based on post-processing three-dimensional hydrodynamical simulations. We find that planets larger than a dimensionless thermal mass of $m=0.05$ corresponding to $0.3$ Earth mass at 1 au or 1.7 Earth masses at 10 au generate dust rings and gaps provided that solids have small Stokes numbers St and that the disk midplane is weakly turbulent ($ diff As dust particles pile up outside the orbit of the planet, the interior gap expands with time when the advective flux dominates over diffusion. Dust gap depths range from a factor of a few to several orders of magnitude, depending on planet mass and the level of midplane particle diffusion. We constructed a semi-analytic model describing the width of the dust ring and gap, and then compared it with the observational data. We find that up to 65&lt;!PCT!&gt; of the observed wide-orbit gaps could be explained as resulting from the presence of a low-mass planet, assuming diff and St However, it is more challenging to explain the observed wide rings, which in our model would require the presence of a population of small particles ($ Further work is needed to explore the role of pebble fragmentation, planet migration, and the effect of multiple planets.

Combined effects of ocean-land processes on spring precipitation variability in Mongolian Plateau

The Mongolian Plateau hosts one of the world's most fragile ecosystems, characterized by high volatility and frequent natural disasters due to rapid climate change and human activities in recent decades. Frequent dust storms notably mark spring in this region. Through observational analysis and numerical modeling, this study investigates the impacts of comprehensive ocean and land processes—including sea surface temperature (SST) in the North Atlantic and Pacific Oceans, as well as Eurasian land conditions—on the interannual fluctuations of spring precipitation in the Mongolian Plateau (SPMP) from 1979 to 2020. The ocean-land processes involve: a tripole pattern of North Atlantic SST anomalies triggers an eastward-propagating continental-scale wave train; Increased snow cover in Central Asia induces significant anomalous low pressure through the albedo effect; El Niño-Southern Oscillation initiate a teleconnection pattern over the upstream region of the Indian-western Pacific Ocean. These anomalous ocean and land conditions interact with large-scale atmospheric circulations, altering dynamical and hydrological conditions around the Mongolian Plateau, thereby contributing to SPMP variation. Further corroboration from numerical model experiments supports the observational analysis results. The combined effects of multiple ocean-land factors effectively explain precipitation variability across extensive areas of the Mongolian Plateau. A regression model constructed using these land-ocean factors captures the time evolution of the SPMP well.

Symmetry breaker governs synchrony patterns in neuronal inspired networks.

Experiments in the human brain reveal switching between different activity patterns and functional network organization over time. Recently, multilayer modeling has been employed across multiple neurobiological levels (from spiking networks to brain regions) to unveil novel insights into the emergence and time evolution of synchrony patterns. We consider two layers with the top layer directly coupled to the bottom layer. When isolated, the bottom layer would remain in a specific stable pattern. However, in the presence of the top layer, the network exhibits spatiotemporal switching. The top layer in combination with the inter-layer coupling acts as a symmetry breaker, governing the bottom layer and restricting the number of allowed symmetry-induced patterns. This structure allows us to demonstrate the existence and stability of pattern states on the bottom layer, but most remarkably, it enables a simple mechanism for switching between patterns based on the unique symmetry-breaking role of the governing layer. We demonstrate that the symmetry breaker prevents complete synchronization in the bottom layer, a situation that would not be desirable in a normal functioning brain. We illustrate our findings using two layers of Hindmarsh-Rose (HR) oscillators, employing the Master Stability function approach in small networks to investigate the switching between patterns.

Mode decomposition to identify oscillation patterns of flexible aeroshell

Flexible aeroshells, featuring deformable membrane surfaces supported by pressurized gas, offer a novel re-entry system for high-altitude deceleration during re-entry. The flexibility of structural components introduces unique challenges in predicting aerodynamic behavior, as deformations can significantly alter the flow field, affecting pressure distribution and potentially causing aerodynamic instabilities. Therefore, coupled analysis is crucial to ensure the performance reliability of inflatable aeroshells. This study investigates the unsteady aerodynamic behavior, considering structural deformation in a two-way partitioned coupled manner in transonic flow. The dominant deformation patterns are identified using dynamic mode decomposition and the greedy compressive sensing algorithm. The findings reveal that the primary deformation pattern combines axial deformation and swing oscillation. The dominant oscillation frequencies remain different from the eigenfrequencies, indicating that the aerodynamic force is the primary driving force of such oscillations. The time evolution of these dominant modes indicates purely oscillatory behavior rather than increasing or decreasing trends. These insights are critical for the design and reliability assessment of inflatable aeroshells in varying aerodynamic environments.

Dynamical maps for accelerating detectors

We study the open quantum dynamics using the language of dynamical maps of a two-level particle detector that starts accelerating through Minkowski vacuum weakly coupled to a massless scalar field. We consider a detector with non-zero size and study its time evolution for the case where it is initially in inertial motion and subsequently a constant acceleration is switched on for a finite time. We study the dynamical maps that describe the evolution of such a system and show that the dynamics is not completely positive (NCP). The inertial motion prior to the acceleration can entangle the detector and field leading to the NCP dynamics. We examine the nature of the open dynamics during the accelerated phase as a function of the duration of prior inertial motion and the magnitude of the acceleration.

A Hydraulic Gradient and Stress-Controlled Erosion Apparatus for Assessing Soil Internal Erosion

Abstract Among the four dominant mechanisms of internal erosion, suffusion appears as one of the most complex. It is indeed the result of the combination of three processes: dislodgement of fine particles, transport of them, and filtration of some fluidized fine particles. These processes depend on the soil’s stress state and on the hydraulic gradient path. Thus, to ensure the repeatability of the suffusion test and to study with accuracy the influence of the aforementioned parameters, a new apparatus was developed. This apparatus is designed to test specimens under a vertical downward flow in hydraulic gradient controlled condition while controlling the confining pressure and the stress deviator, which can be either positive or negative. Ten tests on one cohesionless soil were performed in triaxial conditions, with the same mean effective stress and four different values of stress deviator. To compare with conventional suffusion results, one test is also performed in rigid wall conditions. For all performed tests, the same hydraulic gradient path was applied and particular attention is paid to the repeatability, which implies control of each test step. At the end of each test, the specimen was divided into four layers to measure post-suffusion grain size distributions. The time evolutions of the hydraulic conductivity and the erosion rate permit to identify four different phases. Each phase is characterized by two methods: one based on the hydraulic gradient and the second based on the expended energy by the fluid. The results show the great influence on the suffusion kinetics of the preferential flow paths, which localize in the body of the specimen in triaxial conditions and on the circumference in rigid wall ones. Under a constant mean effective stress, the effect of the stress deviator on the suffusion kinetics appears limited, for the tested soil and shear stress ratios.

Rate Theory model of irradiation effects in UO2: influence of electronic energy losses

To investigate the effect of electronic energy losses on nuclear damage in UO2, we use a simple Rate Theory (RT) model, based on the time evolution of single point defects, governed by their absorption at the surface of TEM lamellae, and by interstitial-type dislocation loops nucleation, solely characterized by their number and average size. We first parametrize the model by fitting six different experimental datasets at various temperatures, ion type and energy (0.39 MeV Xe and 4 MeV Au ion irradiations at 93, 298 and 873 K) where defect evolution in UO2 is dominated by displacement damage caused by nuclear energy losses. The model suggests that dislocation evolution kinetics is driven by monomers diffusion at 873 K. At lower temperature (93 and 298 K) monomer diffusion has little impact and the evolution is governed by the nucleation of loops within the collision cascade. Analysis of four additional experimental datasets at 93 and 298 K where electronic energy losses are strong (single 6 MeV Si and dual simultaneous Xe & Si ion irradiations) required modification of monomer's diffusion coefficients. In the case of single Si ion irradiation, evolution is temperature independent and the enhanced diffusion due to electronic excitations and ionizations are best captured by adding athermal component to the monomer diffusion coefficients. In case of the dual Xe & Si ions irradiation, electronic excitation caused by Si ions impacts the defects pre-generated by Xe ions and enhances defect diffusion by at local heating induced by the thermal spike of Si ions. This effect is best captured by artificially raising the irradiation temperature.

Kinetics of Adsorption-Induced Deformation of Microporous Carbons.

Equilibrium and kinetic behavior of adsorption-induced deformation have attracted a lot of attention in the last few decades. The theoretical and experimental works cover activated carbons, coals, zeolites, glasses, etc. However, most of the theoretical works describe only the equilibrium part of the deformation process or focus on the time evolution of the adsorption process. The present paper aims to cover the existing gap using the thermodynamic framework combined with the diffusion-based description of adsorbate time evolution inside an adsorbent. We obtained self-consistent equations describing equilibrium and out-of-equilibrium adsorption, as well as deformation processes. Further, the obtained equations were verified on the experimental data of carbon dioxide and methane on activated carbons. The model is capable of describing both equilibrium and kinetic adsorption and adsorption-induced deformation data. Additionally, we studied the possible influence of slow relaxation processes in the adsorbent on the adsorption process. The current work helps to interpret experimental data for time-dependent adsorption-induced deformation.