Unified description of electrostatic soliton dynamics and non-adiabatic equations of state in plasmas
IIn this work we seek to investigate plasmas characterized by different density distributions: Boltzmann, Thomas-Fermi, Kappa and Tsallis. Initially, we modified the electrostatic field equation, that is, the Poisson equation, in relation to the type of density distribution. As a result, we obtained a unified description of electrostatic solitons from a generalization of the Korteweg-de Vries equation (KdV). Our formalism demonstrates that, regardless of the type of density distribution of particles in a plasma, it is possible to construct the Korteweg-de Vries equation, via a perturbative reductive method, as long as we are in the proper frame given by the critical Mach number and we proceed to the normalization of the electrostatic potential in terms of the correct energy scale, related to each distribution. As an application of this approach, we demonstrate how the perturbative reductive technique is no longer valid for the interval 3/2 < κ ≤ 5/2 - where κ is the index that describes the suprathermal electrons in the Kappa distribution - which contrasts
with results obtained in the literature. We also characterize the appropriate frameworks that validate the perturbative reductive method for each distribution, thus obtaining the subsonic framework for the Thomas-Fermi distribution, the sonic framework for the Boltzmann distribution and supersonic frameworks for the non-extensive Kappa and Tsallis distributions. Next, we modify the pressure term of the momentum equation of a warm plasma as a function of the Kappa and Tsallis distributions to obtain non-adiabatic equations of state. As a result, we show how the solar wind in the Earth's magnetopause is correctly described by these
equations of state. Finally, we construct a non-extensive generalization of the Bohm-Gross dispersion relation that describes the Langmuir waves; we show that when the non-extensive index approaches −0.36 and −0.71, the coefficients of determination for the well-known van Hoven and Derfler & Simonen dispersion data lie around 0.94 and 0, 85, respectively, values that are extremely satisfactory.