Theory of Quark-Gluon Plasma and Phase Transition

Nonperturbative picture of strong interacting quark-gluon plasma is given based on the systematic Field Correlator Method. Equation of state, phase transition in density-temperature plane is derived and compared to lattice data as well as subsequent thermodynamical quantities of QGP.Comment: 6 pages,5 figures; talk given at "13th Lomonosov Conference on Elementary Particle Physics", Moscow, August 23 -- 29, 2007; new reference adde

Self-inhibiting thermal conduction in high-beta, whistler-unstable plasma

A heat flux in a high-$\beta$ plasma with low collisionality triggers the whistler instability. Quasilinear theory predicts saturation of the instability in a marginal state characterized by a heat flux that is fully controlled by electron scattering off magnetic perturbations. This marginal heat flux does not depend on the temperature gradient and scales as $1/\beta$. We confirm this theoretical prediction by performing numerical particle-in-cell simulations of the instability. We further calculate the saturation level of magnetic perturbations and the electron scattering rate as functions of $\beta$ and the temperature gradient to identify the saturation mechanism as quasilinear. Suppression of the heat flux is caused by oblique whistlers with magnetic-energy density distributed over a wide range of propagation angles. This result can be applied to high-$\beta$ astrophysical plasmas, such as the intracluster medium, where thermal conduction at sharp temperature gradients along magnetic-field lines can be significantly suppressed. We provide a convenient expression for the amount of suppression of the heat flux relative to the classical Spitzer value as a function of the temperature gradient and $\beta$. For a turbulent plasma, the additional independent suppression by the mirror instability is capable of producing large total suppression factors (several tens in galaxy clusters) in regions with strong temperature gradients.Comment: accepted to JP

Wave Functions and Energy Terms of the SCHR\"Odinger Equation with Two-Center Coulomb Plus Harmonic Oscillator Potential

Schr\"odinger equation for two center Coulomb plus harmonic oscillator potential is solved by the method of ethalon equation at large intercenter separations. Asymptotical expansions for energy term and wave function are obtained in the analytical form.Comment: 4 pages, no figures, LaTeX, submitted to PR

On integration of the Kowalevski gyrostat and the Clebsch problems

For the Kowalevski gyrostat change of variables similar to that of the Kowalevski top is done. We establish one to one correspondence between the Kowalevski gyrostat and the Clebsch system and demonstrate that Kowalevski variables for the gyrostat practically coincide with elliptic coordinates on sphere for the Clebsch case. Equivalence of considered integrable systems allows to construct two Lax matrices for the gyrostat using known rational and elliptic Lax matrices for the Clebsch model. Associated with these matrices solutions of the Clebsch system and, therefore, of the Kowalevski gyrostat problem are discussed. The Kotter solution of the Clebsch system in modern notation is presented in detail.Comment: LaTeX, 24 page

Quantization of binding energy of structural solitons in passive mode-locked fiber lasers

On basis of numerical simulation of fiber laser passive mode locking, we have determined the quantum binding-energy levels for a pair of interacting structural solitons. These solitons have powerful wings and correspondingly large binding energies. It has been found that the field amplitude functions for steady states corresponding to neighboring energy levels have opposite parity. We have pointed out the analogy between the energy quantization for laser bound solitons and for a particle moving in potential well. The possibility of a coexistence of in-, opposite-, and π/2-phase soliton pairs has been found. In the case of multiple soliton trains, we have demonstrated the realization of highly stable soliton sequences with any required distribution along the soliton train of various types of bonds between neighboring pulses

Peculiarities of soliton formation in passive mode-locked lasers with anisotropic fibers

Date du colloque : 06/2010International audienc

Regimes of Passive Mode-Locking of Fiber Lasers

We present results of a numerical simulation and analysis of various regimes of passive mode-locking of fiber lasers including a single pulse  and multipulse operation, bound states of solitons, and harmonic passive mode-locking. Our results on the multipulse regimes consist of the multihysteresis dependences of a number of pulses in the laser cavity, of pulse peak intensities and an intracavity radiation energy on a pump power. The analysis of mechanisms of an intersoliton interaction in the laser cavity has been performed. The opportunity of the coding of information with the use of bound soliton sequences has been demonstrated. Various mechanisms for control of intersoliton interactionr are proposed

Passive mode-locked fiber lasers: multiple pulse regimes and operation of high-energy pulses

On basis of numerical simulation we have investigated the multihysteresis phenomena in fiber mode-locked lasers, the regimes of multipulse operation, and the generation of high-energy pulses due to the dissipative soliton resonance. The obtained results ar