The effect of small deviations from a Maxwellian equilibrium on turbulent momentum transport in tokamak plasmas is considered. These non-Maxwellian features, arising from diamagnetic effects, introduce a strong dependence of the radial flux of cocurrent toroidal angular momentum on collisionality: As the plasma goes from nearly collisionless to weakly collisional, the flux reverses direction fr...

Elaborating on a Maxwellian representation of longitudinal wave propagation in a viscothermal fluid, a general nonlocal macroscopic theory of sound propagation in homogeneous porous media saturated with a viscothermal fluid has been recently proposed. The present paper validates this new nonlocal Maxwellian theory by showing that, in the case of the propagation in straight circular tubes, it is...

We introduce and discuss a linear Boltzmann equation describing dissipative interactions of a gas of test particles with a fixed background. For a pseudo-Maxwellian collision kernel, it is shown that, if the initial distribution has finite temperature, the solution converges exponentially for large–time to a Maxwellian profile drifting at the same velocity as field particles and with a universa...

The stability of the Maxwellian of the Boltzmann equation with a large amplitude external potential Φ has been an important open problem. In this paper, we resolve this problem with a large C−potential in a periodic box T, d ≥ 3. We use [1] in Lp−L∞ framework to establish the well-posedness and the L∞−stability of the Maxwellian μE(x, v) = exp { − |v| 2 2 − Φ(x) } .

For the simulation of gate oxide tunneling currents in sub-quarter-micron devices, the correct modeling of the electron energy distribution function is crucial. Our approach is based on a recently presented transport model which accounts for six moments of the Boltzmann transport equation. A corresponding analytical model for the electron energy distribution function shows good agreement with M...

We study numerically and theoretically (on a heuristic level) the time evolution of a gas confined to a cube of size L divided into two parts by a piston with mass ML ’ L which can only move in the x-direction. Starting with a uniform ‘‘double-peaked’’ (non Maxwellian) distribution of the gas and a stationary piston, we find that (a) after an initial quiescent period the system becomes unstable...

We investigate the long-time behavior of a system of viscoelastic particles modeledwith the homogeneous Boltzmann equation.We prove the existence of a universal Maxwellian intermediate asymptotic state with explicit rate of convergence towards it. Exponential lower pointwise bounds and propagation of regularity are also studied. These results can be seen as a generalization of several classical...