Kappa distributions in the framework of superstatistics
Abstract
The kappa distribution of velocities appears routinely in the study of collisionless plasmas present in Earth's magnetosphere, the solar wind among other contexts where particles are unable to reach thermal equilibrium. Originally justified through the use of Tsallis' non-extensive statistics, nowadays there are alternative frameworks that provide insight into these distributions, such as superstatistics. In this work we review the derivation of the multi-particle and single-particle kappa distributions for collisionless plasmas within the framework of superstatistics, as an alternative to the use of non-extensive statistics. We also show the utility of the superstatistical framework in the computation of expectation values under kappa distributions. Some consequences of the superstatistical formalism regarding correlations, temperature and entropy of kappa-distributed plasmas are also discussed.
Cite
@article{arxiv.2507.03757,
title = {Kappa distributions in the framework of superstatistics},
author = {Sergio Davis and Biswajit Bora and Cristian Pavez and Leopoldo Soto},
journal= {arXiv preprint arXiv:2507.03757},
year = {2025}
}