Is the Vlasov equation valid for Yukawa plasmas?

  • K.I. Golden
  • G.J. Kalman
  • L.G. Silvestri


We analyze the Vlasov dispersion relation for Yukawa plasmas in three dimensions for the purpose of identifyingcoupling parameter domains where the Vlasov approach is justified and the existence of a well-developed RPAtype collective excitation is allowed. We establish a rigorous lower bound for the coupling parameter, belowwhich there can be no real solution to the Vlasov dispersion relation. In the coupling domain, where weaklydamped solutions do exist, we have focused on the long-wavelength acoustic regime where we establish morerestrictive estimates for the lower bound of the coupling parameter. We also derive a general formula for thecorresponding acoustic phase velocity, valid over a wide range of coupling parameter/screening parameter ratiosabove the lower bound. We conclude that the Vlasov approach is tenable only above a critical coupling value.Comparison with Molecular Dynamics simulation results further highlights the limitations of the Vlasovapproximation for weakly coupled Yukawa plasmas.
How to Cite
GOLDEN, K.I.; KALMAN, G.J.; SILVESTRI, L.G.. Is the Vlasov equation valid for Yukawa plasmas?. Physical Sciences and Technology, [S.l.], v. 4, n. 1, p. 9-14, june 2018. ISSN 2409-6121. Available at: <>. Date accessed: 28 oct. 2021. doi:
Plasma Physics and Related Technology