34 research outputs found

    The pandemic of viruses with a long incubation phase in the small world

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    A model of the spread of viruses in selected city and in a network of cities is considered, taking into account the delay caused by the long incubation period of the virus. The effect of delay effects is shown in comparison with pandemics without such delay. A temporary asymmetry of the spread of infection has been identified, which means that the time for a pandemic to develop significantly exceeds the time for its completion. Model calculations of the spread of viruses in a network of interconnected large and small cities were carried out, and dynamics features were revealed in comparison with the spread of viruses in a single city, including the possibility of reinfection of megalopolis

    Control of the Exciton Transfer in Quantum Dots by the Stark Effect

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    Resonant transfer of energy between excited states in a system of two semiconductor quantum dots is studied theoretically. The model Hamiltonian has been formulated, which allowed describe the impact on the dynamics of the resonant laser pulse, the Coulomb interaction, the static Stark effect, and the relaxation of the exciton states. Examples of calculations for efficiency of the energy transfer under different excitation conditions are presented. The control of the process by the level shift in a constant electric field is demonstrated

    Scenarios of Destruction for Large Network and Increasing Reliability

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    Damage scenarios for large networks are considered. The cascade scenario is described by means of powers of adjacency matrix. More difficult probabilistic variants of the large network damage are modeling by Markov chains. For reliability augmentation of networks we add a set of random intermediate agents with big dimensionality. It provides high reliability of all system even with low reliability of single components. Probabilistic estimation of reliability for reinforced network is made

    Mathematical Model of Age Aggression

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    We formulate a mathematical model of competition for resources between representatives of different age groups. A nonlinear kinetic integral-differential equation of the age aggression describes the process of redistribution of resources. It is shown that the equation of the age aggression has a stationary solution, in the absence of age-dependency in the interaction of different age groups. A numerical simulation of the evolution of resources for different initial distributions has done. It is shown the instability of the system and the existence of regimes leading to a concentration of resources in the certain age groups

    Forced quantum inverted oscillator

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    New exact and asymptotic results for a quantum inverted oscillator, driven by the variable external force, are presented. To illustrate the advantages of our approach, we applied the obtained propagator to the descriptions of evolution the initial Gaussian wave packet under arbitrary time-dependent force or a {\delta}-pulse action. The alternative problem of tunneling a particle through a parabolic barrier under the influence of a low-frequency harmonic force we solve in the quasistatic approximation. Going to the Heisenberg picture in the Caldeira-Leggett model, we describe the influence of a time-dependent force on an open inverted oscillator. The resulting dynamics is presented in the form of combination the evolution of the average value of a coordinate operator and the stochastic diffusion, being induced the wave packet spreading and the Brownian motion

    Radiation of tunnel electron

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    The photorecombination radiation on a neighbor center of an electron ionized in the nonlinear tunneling regime is discussed. In the framework of the active electron model an analytical solution of the problem has been obtained. The analytical solution for distribution of the radiation energy spectrum has been derived both for one and three dimension problems. The optimal parameters of the field and the distance between quantum wells for a process of effective photorecombination with a broad spectrum have been formulated.Comment: 8 pages, 3 figure

    Interference at the tunnel ionization from double-center potential

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    The tunnel ionization of an electron bounded by two delta potentials under the influence of a constant electric field is considered. The equations for the electron current density for two different initial states are obtained. The dependence of the emission current on the orientation of the potential with respect to the field direction and the distance between them is studied. Appropriate conditions for observation essential interference effects are defined.Comment: 7 pages, 2 figure

    The complex-valued encoding for dicision-making based on aliasing data

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    It is proposed a complex valued channel encoding for multidimensional data. The basic approach contains overlapping of complex nonlinear mappings. Its development leads to sparse representation of multi-channel data, increasing their dimensions and the distance between the images

    Nonlinear electron emission under the action of ultrashort laser pulse

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    The process of nonlinear electron emission from a metal surface under the action of femtosecond laser pulse with moderate intensity ∼1011\sim10^{11}~W/cm2^2 is considered. One-dimensional model is formulated, taking into account the advantage of the pp-polarized light in the nonlinear emission. The time dependent Schrodinger equation with fixed equilibrium boundary conditions is solved in the half-space using the Laplace transform technique. The energy spectrum of emitted electrons is obtained, and its dependence on the laser pulse parameters in compare with experimental data is discussed.Comment: 7 pages, 3 figure

    The response of an electron in the image potential on the external steady fields

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    The exact wave functions, which describe the states of an electron, bound in the image potential, and the magnetic field, which is perpendicular to surface of a metal, are obtained. The correction terms to the energy of an electron in the first order of the perturbation theory with respect to the interaction with the external electric field are calculated. The possibility of experimental measurement of a local electric field by the level shift is analyzed
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