Beyond Boltzmann: Modelling Non-Equilibrium Space Plasmas Through Kappa Distributions

• Grant number: 24/02295-2
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2024
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Agreement: CNPq
• Principal Investigator: Jose Ademir Sales de Lima
• Grantee: Jose Ademir Sales de Lima
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/51676-9 - LLAMA: a mm/submm radiotelescope in the Andes, in collaboration with Argentina, AP.TEM
• Associated scholarship(s): 24/14163-3 - Beyond Boltzmann: Modelling Non-Equilibrium Space Plasmas Through Kappa Distributions, BP.JD

Abstract

In this project we investigate space plasmas out of thermodynamic equilibrium based onkappa (non-Gaussian) distributions. The standard kappa distribution has been the mostexplored statistical tool to study the suprathermal component of space plasmas in solarwinds and planetary magnetospheres. The basic reason is its agreement with measurementsfrom missions like Voyager, HELIOS, WIND, Cluster spacecraft and the Parker Solar Probe.However, as an empirical distribution, it has only a finite number of non-divergent velocitymoments. Such a problem was solved by the regularized kappa distribution, proposed forsuppressing the singularities plaguing the standard kappa distribution. In this context, wewill derive the suprathermal equation of state based on the improved kappa distribution.This result leads naturally to the equation describing the spatial and temporal evolution ofthe electron distribution in the heliosphere thereby allowing us to study the instability andelectromagnetic wave emissions (bursts) occurring in the interaction of solar winds with theinterplanetary plasma. Such results will be confronted with the observational data releasedby the space plasma probes. As an extra bonus, all the kappa predictions will be comparedwith the ones derived from the non-Gaussian Tsallis statistics. (AU)