Open AccessOn the origin of the polytropic behavior in space plasmas
Author(s) -
G. Livadiotis
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1332/1/012010
Subject(s) - polytropic process , physics , plasma , space (punctuation) , connection (principal bundle) , particle (ecology) , astrophysical plasma , classical mechanics , distribution (mathematics) , statistical physics , mechanics , mathematical analysis , mathematics , geometry , quantum mechanics , geology , linguistics , philosophy , oceanography
The paper addresses the connection between the polytropic behavior – the specific power-law relationship among the thermal plasma moments– and the functional form of the distribution of particle velocities and energies. Surprisingly, the polytropic behavior requires the statistical mechanics of the plasma particles to turn to the framework of kappa distributions. While it was already known that kappa distributions can lead to the polytropic relationship, the new result shows that the reverse derivation is also true; thus, the polytropic behavior has the role of a mechanism generating kappa distributions. Therefore, when observations confirm the existence of a polytropic behavior in plasma particles, then the framework of kappa distributions for describing particle velocities and energies can be indirectly confirmed.