1984/07/01 by F. Pegoraro, Ф. Пегораро, Francesco Porcelli +1 · 24 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Adiabatic process #Classical mechanics #Dust and Plasma Wave Phenomena #Electron #Equation of state #Gas Dynamics and Kinetic Theory #High-pressure geophysics and materials #Isothermal process #Physics #Plasma #Plasma modeling #Polytropic process #Quantum electrodynamics #Quantum mechanics #Relativistic particle #Relativistic plasma #Thermodynamics #Vlasov equation
paper · doi:10.1063/1.864820
published in The Physics of Fluids 27(7), 1665-1670 (AIP Publishing)
openalex publication_date 1984/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/25
It is shown that in a fully relativistic plasma an isothermal equation of state must be assumed in order to obtain from fluid equations the correct dispersion equation of longitudinal plasma waves. This isothermal equation of state contrasts with the adiabatic equation that applies to a non-relativistic plasma. For arbitrary values of the ratio α between the particle rest mass and particle temperature, a polytropic equation of state must be introduced. The dependence of the polytropic index γ on α can be derived from the relativistic Vlasov equation and can be shown to join the adiabatic (α≫1) and the isothermal (α≪1) regimes smoothly.