English

Regularized $\kappa$-distributions with non-diverging moments

Plasma Physics 2018-02-09 v3 Space Physics

Abstract

For various plasma applications the so-called (non-relativistic) κ\kappa-distribution is widely used to reproduce and interpret the suprathermal particle populations exhibiting a power-law distribution in velocity or energy. Despite its reputation the standard κ\kappa-distribution as a concept is still disputable, mainly due to the velocity moments MlM_{l} which make possible a macroscopic characterization, but whose existence is restricted only to low orders l<2κ1l < 2\kappa-1. In fact, the definition of the κ\kappa-distribution itself is conditioned by the existence of the moment of order l=2l=2 (i.e., kinetic temperature) satisfied only for κ>3/2\kappa > 3/2. In order to resolve these critical limitations we introduce the regularized κ\kappa-distribution with non-diverging moments. For the evaluation of all velocity moments a general analytical expression is provided enabling a significant step towards a macroscopic (fluid-like) description of space plasmas, and, in general, any system of κ\kappa-distributed particles.

Keywords

Cite

@article{arxiv.1802.00735,
  title  = {Regularized $\kappa$-distributions with non-diverging moments},
  author = {K. Scherer and H. Fichtner and M. Lazar},
  journal= {arXiv preprint arXiv:1802.00735},
  year   = {2018}
}

Comments

6 pages ,5 figures

R2 v1 2026-06-23T00:08:54.733Z