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Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment
The Boltzmann–Gibbs (BG) entropy has been used in a wide variety of problems for more than a century. It is well known that BG entropy is additive and extensive, but for certain systems such as those dictated by long-range interactions, it is speculated that the entropy must be non-additive and non-...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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MDPI
2019
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515349/ http://dx.doi.org/10.3390/e21090820 |
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author | Yoon, Peter H. |
author_facet | Yoon, Peter H. |
author_sort | Yoon, Peter H. |
collection | PubMed |
description | The Boltzmann–Gibbs (BG) entropy has been used in a wide variety of problems for more than a century. It is well known that BG entropy is additive and extensive, but for certain systems such as those dictated by long-range interactions, it is speculated that the entropy must be non-additive and non-extensive. Tsallis entropy possesses these characteristics, and is parameterized by a variable q ([Formula: see text] being the classic BG limit), but unless q is determined from microscopic dynamics, the model remains a phenomenological tool. To this day, very few examples have emerged in which q can be computed from first principles. This paper shows that the space plasma environment, which is governed by long-range collective electromagnetic interaction, represents a perfect example for which the q parameter can be computed from microphysics. By taking the electron velocity distribution function measured in the heliospheric environment into account, and considering them to be in a quasi-equilibrium state with electrostatic turbulence known as quasi-thermal noise, it is shown that the value corresponding to [Formula: see text] , or alternatively [Formula: see text] , may be deduced. This prediction is verified against observations made by spacecraft, and it is shown to be in excellent agreement. This paper constitutes an overview of recent developments regarding the non-equilibrium statistical mechanical approach to understanding the non-extensive nature of space plasma, although some recent new developments are also discussed. |
format | Online Article Text |
id | pubmed-7515349 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-75153492020-11-09 Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment Yoon, Peter H. Entropy (Basel) Article The Boltzmann–Gibbs (BG) entropy has been used in a wide variety of problems for more than a century. It is well known that BG entropy is additive and extensive, but for certain systems such as those dictated by long-range interactions, it is speculated that the entropy must be non-additive and non-extensive. Tsallis entropy possesses these characteristics, and is parameterized by a variable q ([Formula: see text] being the classic BG limit), but unless q is determined from microscopic dynamics, the model remains a phenomenological tool. To this day, very few examples have emerged in which q can be computed from first principles. This paper shows that the space plasma environment, which is governed by long-range collective electromagnetic interaction, represents a perfect example for which the q parameter can be computed from microphysics. By taking the electron velocity distribution function measured in the heliospheric environment into account, and considering them to be in a quasi-equilibrium state with electrostatic turbulence known as quasi-thermal noise, it is shown that the value corresponding to [Formula: see text] , or alternatively [Formula: see text] , may be deduced. This prediction is verified against observations made by spacecraft, and it is shown to be in excellent agreement. This paper constitutes an overview of recent developments regarding the non-equilibrium statistical mechanical approach to understanding the non-extensive nature of space plasma, although some recent new developments are also discussed. MDPI 2019-08-22 /pmc/articles/PMC7515349/ http://dx.doi.org/10.3390/e21090820 Text en © 2019 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Yoon, Peter H. Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment |
title | Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment |
title_full | Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment |
title_fullStr | Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment |
title_full_unstemmed | Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment |
title_short | Thermodynamic, Non-Extensive, or Turbulent Quasi-Equilibrium for the Space Plasma Environment |
title_sort | thermodynamic, non-extensive, or turbulent quasi-equilibrium for the space plasma environment |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515349/ http://dx.doi.org/10.3390/e21090820 |
work_keys_str_mv | AT yoonpeterh thermodynamicnonextensiveorturbulentquasiequilibriumforthespaceplasmaenvironment |