TY - JOUR

T1 - A variational derivation of the velocity distribution functions for nonequilibrium, multispecies, weakly interacting, spherically symmetric many-body systems

AU - Cuperman, S.

AU - Weiss, I.

AU - Dryer, M.

PY - 1982/12

Y1 - 1982/12

N2 - The most probable velocity distribution function of each component, fa, of a nonequilibrium multispecies spherically symmetric system of particles (stellar plasma atmospheres and winds, stellar systems, pellet-fusion systems) is analytically derived for the case in which each component is described by the first six moments of fa. This is achieved by the aid of a variational approach based on the requirement that the Boltzmann H function for the system be a minimum, subject to the constraints provided by the sets of six macroscopic parameters describing the nonequilibrium state. The use of the so-obtained velocity distribution functions for the closure of the moment equations as well as for the calculation of their collisional terms (via the Fokker-Planck equation) is discussed. The limitations on the maximum deviations from the equilibrium state which are consistent with the assumptions used are also indicated.

AB - The most probable velocity distribution function of each component, fa, of a nonequilibrium multispecies spherically symmetric system of particles (stellar plasma atmospheres and winds, stellar systems, pellet-fusion systems) is analytically derived for the case in which each component is described by the first six moments of fa. This is achieved by the aid of a variational approach based on the requirement that the Boltzmann H function for the system be a minimum, subject to the constraints provided by the sets of six macroscopic parameters describing the nonequilibrium state. The use of the so-obtained velocity distribution functions for the closure of the moment equations as well as for the calculation of their collisional terms (via the Fokker-Planck equation) is discussed. The limitations on the maximum deviations from the equilibrium state which are consistent with the assumptions used are also indicated.

KW - Velocity distribution functions

KW - plasmas-nonequilibrium

KW - stellar systems-nonequilibrium

KW - weakly interacting many-body systems

UR - http://www.scopus.com/inward/record.url?scp=34250232974&partnerID=8YFLogxK

U2 - 10.1007/BF01011793

DO - 10.1007/BF01011793

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AN - SCOPUS:34250232974

SN - 0022-4715

VL - 29

SP - 803

EP - 812

JO - Journal of Statistical Physics

JF - Journal of Statistical Physics

IS - 4

ER -