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V. Fortov

Publications and source records attributed to V. Fortov.

6 recordsLinked to original sources
arXiv2020

Screening properties of quark-gluon plasma obtained from distribution and correlation functions of the constituent quasiparticle model

Based on the constituent quasiparticle model of quark-gluon plasma (QGP), the matrix elements of the density operator and the Wigner function in the color phase space are presented in form of color path integrals over Wiener and SU(3) group Haar measures. Monte Carlo calculations of quark and gluon momentum distributions and spatial pair distribution functions have been carried out for the strongly coupled QGP plasma in thermal equilibrium at zero baryon chemical potential. The Debye screening mass and the running coupling constant have been obtained from the spatial pair distribution function and are in agreement with the available lattice QCD data. At densities related to the average interparticle distance more than 0.4 fm the gluon bound states in the form of glueballs have been found. Comparison with the Maxwell Boltzmann distribution shows significant influence of interparticle interaction on high energy asymptotics of the momentum distribution functions, resulting in appearance of quantum tails. The new color pair correlation function has been introduced, and related new color screening mass has been discussed.

nucl-th↗
arXiv2005

Exciton formation and dissociation in mass-asymmetric electron-hole plasmas

First-principle path integral Monte Carlo simulations were performed in order to analyze correlation effects in complex electron-hole plasmas, particularly with regard to the appearance of excitonic bound states. Results are discussed in relation to exciton formation in unconventional semiconductors with large electron hole mass asymmetry.

cond-mat.str-el↗
arXiv2004

Measurement of the Ion Drag Force in a Complex DC-Plasma Using the PK-4 Experiment

The force on a microparticle in a complex plasma by streaming ions, the so-called ion drag force, is not well known. However, it is important for the understanding of interesting phenomena in complex plasmas such as the void formation under microgravity conditions. The PK-4 experiment, which is developed for a later use on board of the International Space Station, is ideally suited for investigating this problem. In this experiment a complex DC-plasma is created in a glass tube in which the microparticles flow from the cathode to the anode. Measuring the microparticle velocities, the forces on the particles for different particle sizes, pressures, and DC-currents can be extracted by assuming force balance. Experiments have been performed in the laboratory as well as under microgravity using parabolic flights. The results of these experiments will be presented and compared to theoretical predictions.

physics.plasm-ph↗
arXiv2002

Interacting electrons in a one-dimensional random array of scatterers - A Quantum Dynamics and Monte-Carlo study

The quantum dynamics of an ensemble of interacting electrons in an array of random scatterers is treated using a new numerical approach for the calculation of average values of quantum operators and time correlation functions in the Wigner representation. The Fourier transform of the product of matrix elements of the dynamic propagators obeys an integral Wigner-Liouville-type equation. Initial conditions for this equation are given by the Fourier transform of the Wiener path integral representation of the matrix elements of the propagators at the chosen initial times. This approach combines both molecular dynamics and Monte Carlo methods and computes numerical traces and spectra of the relevant dynamical quantities such as momentum-momentum correlation functions and spatial dispersions. Considering as an application a system with fixed scatterers, the results clearly demonstrate that the many-particle interaction between the electrons leads to an enhancement of the conductivity and spatial dispersion compared to the noninteracting case.

cond-mat.dis-nn↗
arXiv2001

Path integral Monte Carlo simulations and analytical approximations for high-temperature plasmas

The results of analytical approximations and extensive calculations based on a path integral Monte Carlo (PIMC) scheme are presented. A new (direct) PIMC method allows for a correct determination of thermodynamic properties such as energy and equation of state of dense degenerate Coulomb systems. In this paper, we present results for dense partially ionized hydrogen at intermediate and high temperature. We give a quantitative comparison with the available results of alternative (restricted) PIMC simulations and with analytical expressions based on iterpolation formulas meeting the exact limits at low and high densities. Good agreement between the two simulations is found up to densities of the order of $10^{24}cm^{-3}$. The agreement with the analytical results is satisfactory up to densities in the range $10^{22}... 10^{23}cm^{-3}$.

astro-ph↗