Ensemble dependence of fluctuations with application to machine computations

J. L. Lebowitz, Jerome Percus, L. Verlet

Research output: Contribution to journalArticle

Abstract

The standard theory of fluctuations in thermodynamic variables in various ensembles is generalized to nonthermodynamic variables: e.g., the mean-square fluctuations of the kinetic energy K in a classical microcanonical ensemble at fixed energy E is given, for large systems, by(δK)2K=T[1-32C), where T is the temperature (corresponding to the energy E) and C is the specific heat per particle (in units of Boltzmann's constant). The general results may be expressed in terms of the asymptotic behavior of the Ursell functions in various ensembles. Applications are made to molecular dynamic computations where time averages correspond (via ergodicity) to phase averages in an ensemble with fixed energy and momentum. The results are also useful for time-dependent correlations.

Original languageEnglish (US)
Pages (from-to)250-254
Number of pages5
JournalPhysical Review
Volume153
Issue number1
DOIs
StatePublished - 1967

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energy
kinetic energy
specific heat
molecular dynamics
momentum
thermodynamics
temperature

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Ensemble dependence of fluctuations with application to machine computations. / Lebowitz, J. L.; Percus, Jerome; Verlet, L.

In: Physical Review, Vol. 153, No. 1, 1967, p. 250-254.

Research output: Contribution to journalArticle

Lebowitz, J. L. ; Percus, Jerome ; Verlet, L. / Ensemble dependence of fluctuations with application to machine computations. In: Physical Review. 1967 ; Vol. 153, No. 1. pp. 250-254.
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