169 research outputs found
Comparison of Boltzmann Kinetics with Quantum Dynamics for a Chiral Yukawa Model Far From Equilibrium
Boltzmann equations are often used to describe the non-equilibrium
time-evolution of many-body systems in particle physics. Prominent examples are
the computation of the baryon asymmetry of the universe and the evolution of
the quark-gluon plasma after a relativistic heavy ion collision. However,
Boltzmann equations are only a classical approximation of the quantum
thermalization process, which is described by so-called Kadanoff-Baym
equations. This raises the question how reliable Boltzmann equations are as
approximations to the complete Kadanoff-Baym equations. Therefore, we present
in this article a detailed comparison of Boltzmann and Kadanoff-Baym equations
in the framework of a chirally invariant Yukawa-type quantum field theory
including fermions and scalars. The obtained numerical results reveal
significant differences between both types of equations. Apart from
quantitative differences, on a qualitative level the late-time universality
respected by Kadanoff-Baym equations is severely restricted in the case of
Boltzmann equations. Furthermore, Kadanoff-Baym equations strongly separate the
time scales between kinetic and chemical equilibration. In contrast to this
standard Boltzmann equations cannot describe the process of quantum-chemical
equilibration, and consequently also cannot feature the above separation of
time scales.Comment: 17 pages, 8 figures, REVTeX
Classical, neoclassical and anomalous transport theories. Is Onsager symmetry relevant?
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Hamiltonian nontwist map for magnetic field lines with locally reversed shear in toroidal geometry
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Kinetic theory of the evolution of collective plasma excitations in an external electric field
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Approach to equilibrium of a quantum plasma
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Some reflections on the management of energy resources
SCOPUS: cp.jFLWNAinfo:eu-repo/semantics/publishedScientific Issues of the Next Century: Convocation of World Academie
Projection operations in non-equilibrium statistical mechanics
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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