Nichtstatische interferometrische Messungen an Gasproben

Bärwinkel, Klaus; Hartkämper, A.

doi:10.1524/teme.1969.396407.jg.521

Cited by 4 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is well known that conventional Markovian kinetic equations, besides being limited to time-scales large compared to the correlation time, conserve only kinetic (quasi-particle) energy. It was realized a long time ago [18,4] that the problems of energy conservation and short-time behaviour are closely linked together. Presenting an explicit expression for the potential energy, we show that the non-Markovian kinetic equation does indeed conserve total (the sum of kinetic and potential) energy.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of non-Markovian effects in charge-carrier scattering: one-time versus two-time kinetic equations

Bönitz

Kremp

Scott

et al. 1996

J. Phys.: Condens. Matter

100

108

View full text Add to dashboard Cite

The non-Markovian carrier-carrier scattering dynamics in a dense electron gas is investigated. Within the framework of quantum kinetic equations in the second Born approximation we study the relevance of retardation (memory) effects, energy broadening and correlation build-up for femtosecond relaxation processes. Furthermore, the important issue of total energy conservation, within various well-established approximation schemes, is analysed. The most important non-Markovian effect is shown to be the broadening of the energy delta function leading to an increase of kinetic energy with time. Our numerical analysis includes both the single-time kinetic equation and the full two-time Kadanoff-Baym equations. Our results are expected to correctly reproduce qualitative features of non-Markovian dynamics in plasmas, fluids, nuclear matter and in the intraband relaxation of semiconductors. The comparison of the exact solutions for different approximations allows suggestions for simplifications that make this kind of calculation and their extension, especially to realistic semiconductor situations, more feasible.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical analysis of non-Markovian effects in charge-carrier scattering: one-time versus two-time kinetic equations

Bönitz

Kremp

Scott

et al. 1996

J. Phys.: Condens. Matter

100

108

View full text Add to dashboard Cite

show abstract

“…A first idea to take into account the influence of the initial stage was the gradient expansion with respect to the retardation [1,2,5,6]. With this expansion, Klimontovich and Ebeling and also Baerwinkel obtained kinetic equations with conservation laws for nonideal systems.…”

Section: Figure 1 Stages Of Relaxation Of a Many-particle Systemmentioning

confidence: 99%

Short-time kinetics and initial correlations in quantum kinetic theory

Kremp

Semkat

Bönitz

2005

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

There are many reasons to consider quantum kinetic equations describing the evolution of a many-particle system on ultrashort time scales, e.g. correct energy conservation in nonideal plasmas, buildup of correlations (bound states), and kinetics of ultrafast processes in short-pulse laser plasmas. These problems have been always an central and important field of research of Yu. L. Klimontovich. We present a quantum kinetic theory including initial correlations and being valid on arbitrary time scales. Various examples of short-time relaxation processes, such as relaxation of the distribution function and the energy, are shown. Furthermore, gradient expansions of the general equations and the role of bound states are discussed.

show abstract

“…is obtained [3,4] with J B [f W ] as Boltzmann's collision integral depending on f W . Here Ψ is just the functional (5) with the kernels…”

Section: Quantum Statistical Backgroundmentioning

confidence: 99%

“…Strong repulsion reduces the freely accessible volume for gas particles. Because of this effect, called "van der Waals blocking", more than just (2π ) 3 is needed as an elementary cell volume v el ( p 1 ) = (2π ) 3…”

Section: Quasi-particle Picture For Equilibriummentioning

confidence: 99%

Quasi-particle picture for monatomic gases

Bärwinkel

Schnack

Thelker

1999

Physica A: Statistical Mechanics and its Applications

View full text Add to dashboard Cite

A quasi-particle theory for monatomic gases in equilibrium is formulated and evaluated to yield the exact virial contributions to the thermodynamic state functions in lowest order of the density. Van der Waals blocking has necessarily to be accounted for in occupation number statistics. The quasi-particle distribution function differs from the Wigner function by a bilinear functional thereof. The progress made so far is promising with respect to a corresponding version of kinetic theory.

show abstract

Nichtstatische interferometrische Messungen an Gasproben

Cited by 4 publications

References 0 publications

Numerical analysis of non-Markovian effects in charge-carrier scattering: one-time versus two-time kinetic equations

Numerical analysis of non-Markovian effects in charge-carrier scattering: one-time versus two-time kinetic equations

Short-time kinetics and initial correlations in quantum kinetic theory

Quasi-particle picture for monatomic gases

Contact Info

Product

Resources

About