C.G. van Weert

On relativistic kinetic gas theory: II. Reciprocal relations between transport phenomena

Abstract Relativistic reciprocal relations between the cross effects of heat conduction and diffusion are derived from time reversal invariance for a gas mixture, which obeys the linearized relativistic transport equation.

On relativistic kinetic gas theory. III: The non-relativistic limit and its range of validity

Abstract It is discussed how the non-relativistic theory may be obtained as an approximation from the covariant theory by means of expansions in powers of c -1 ( c is the velocity of light) and by an appropriate treatment of the c 2 (rest mass energy) terms. One finds the non-relativistic expressions for the thermodynamic and transport properties as the terms of order c 0 . The first corrections to these results are all of the order c -2 .

Relativistic onsager relations in kinetic gas theory

Abstract Reciprocal Onsager relations are derived from microscopic reversibility and the relativistic Boltzmann equation for a gas mixture in which heat conduction, diffusion, viscous flow and cross-effects occur.

Bulk viscosity of degenerate neutrinos

An expression for the bulk viscosity due to beta absorption in a system of neutrinos, neutrons, protons, and electrons is given. It generalizes a number of previously published results which are discussed and compared. It is stressed that the derivation is based on the condition of local beta equilibrium.

On the role of space and time symmetries in kinetic theory

Abstract The conservation and entropy laws are derived from the transport equation for a mixture of molecules with spherically symmetrical interaction without the use of symmetry properties for the collision rate. On the other hand, rotational invariance of the collision rate is used to obtain phenomenological relations in accordance with Curies law for isotropic systems, while reciprocal Onsager relations between the transport phenomena are deduced from time reversal invariance alone.

Effects of neutrino-electron scattering on neutrino transport in Type II Supernovae

We investigate the effects of neutrino-electron scattering on electron-neutrino transport during the collapse phase of a Type II supernova. Calculations of stationary state transport were performed on a 1.17 {ital M}{sub {circle_dot}} spherically symmetric infall model, with neutrino-electron scattering turned off and on. During the transport calculation, the stellar background is kept fixed in time. In this manner, we are able to isolate the effects of neutrino-electron scattering on neutrino transport alone. We find that the inclusion of neutrino-electron scattering approximately doubles the emitted neutrino flux during infall. Neutrino-electron scattering increases the rate at which energy and lepton number are transferred from the matter to the neutrinos. However, the transfer of entropy to the matter increases in a large part of the collapsing core. We also discuss the equilibration of the neutrinos. {copyright} {ital 1996 The American Astronomical Society.}

Relativistic entropy law for a gas mixture outside equilibrium

Abstract The Gibbs relation and the entropy source strength for a mixture (in which heat conduction, diffusion, viscous flow and cross-effects occur) are derived in the first Enskog approximation of relativistic kinetic gas theory.

Finite-temperature renormalization of the ({phi}{sup 4}){sub 4}-model

We summarize results of the finite-temperature renormalization group approach, formalized by Matsumoto, Nakano and Umezawa in 1984, for the λ(ϕ4)4-model. The flow parameter is the reference temperature at which the mass parameter and the coupling constant of the theory are defined through renormalization conditions. We derive flow equations to one-loop order, and integrate numerically from zero temperature to above the critical temperature. The mass and the coupling constant both vanish at the critical temperature, and are positive below and above the critical region. In the critical region dimensional reduction to an effective 3D theory takes place. The leading behavior of the mass at high temperature is linear with a small logarithmic sub-leading contribution.

Finite-Temperature Renormalization of the (phi4)_4-model

We summarize results of the finite-temperature renormalization group approach, formalized by Matsumoto, Nakano and Umezawa in 1984, for the λ(ϕ4)4-model. The flow parameter is the reference temperature at which the mass parameter and the coupling constant of the theory are defined through renormalization conditions. We derive flow equations to one-loop order, and integrate numerically from zero temperature to above the critical temperature. The mass and the coupling constant both vanish at the critical temperature, and are positive below and above the critical region. In the critical region dimensional reduction to an effective 3D theory takes place. The leading behavior of the mass at high temperature is linear with a small logarithmic sub-leading contribution.

Thermal conductivity of normal liquid3He at finite temperatures

Greywalls experimental data for the thermal conductivity of normal liquid3He are reanalyzed. The temperature dependence at various pressures seems consistent with a law of corresponding states in the sense that it can be described by a universal function of a reduced temperature. It is suggested that the appreciable dynamical screening of the scattering amplitude for the quasiparticles in3He is responsible for this behavior. For illustration the thermal conductivity is calculated at finite temperature for a class of screened interaction models to leading order in the screening parameter. Good agreement is found with experiment by fitting the single Landau parameterAa0.