English
Related papers

Related papers: Relationship between polytropic index and temperat…

200 papers

We use standard polynomial expansion technique to show the existence of a relation between polytropic model and the description of gas spheres at finite temperature. A numerical analysis is made concerning the obtained perturbative…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-24 Claudio M. G. de Sousa , Evandro A. de Araujo

The relaxation rate of a Maxwellian velocity distribution function that has an initially anisotropic temperature $(T_\parallel \neq T_\perp)$ is an important physical process in space and laboratory plasmas. It is also a canonical example…

Plasma Physics · Physics 2017-06-07 Scott D. Baalrud , Jerome Daligault

A magnetic field was recently shown to enhance field-parallel heat conduction in a strongly correlated plasma whereas cross-field conduction is reduced. Here we show that in such plasmas, the magnetic field has the additional effect of…

Plasma Physics · Physics 2017-01-25 T. Ott , M. Bonitz , P. Hartmann , Z. Donkó

The recently developed concept of "entropic defect" is important for understanding the foundations of thermodynamics in space plasma physics, and more generally, for systems with physical correlations among their particles. Using this…

Plasma Physics · Physics 2022-11-30 George Livadiotis , David J. McComas

Using the gauge/gravity duality we study the imaginary part of the static potential associated to the thermal width in finite temperature strongly coupled anisotropic plasma. We firstly derive the potential for a generic anisotropic…

High Energy Physics - Theory · Physics 2013-12-03 Kazem Bitaghsir Fadafan , Dimitrios Giataganas , Hesam Soltanpanahi

The new in situ measurements of the Solar Orbiter mission contribute to the knowledge of the suprathermal populations in the solar wind, especially of ions and protons whose characterization, although still in the early phase, seems to…

Solar and Stellar Astrophysics · Physics 2024-09-17 S. M. Shaaban , R. A. Lopez , M. Lazar , S. Poedts

The power spectrum of temperature anisotropies induced by hot intracluster gas on the cosmic background radiation is calculated. For low multipoles it remains constant while at multipoles above $l>2000$ it is exponentially damped. The shape…

Astrophysics · Physics 2009-10-31 F. Atrio Barandela , J. P. Muecket

We derive annual skymaps of the proton temperature in the inner heliosheath (IHS), and track their temporal evolution over the years from 2009 to 2016 of Interstellar Boundary Explorer observations. Other associated thermodynamic parameters…

Solar and Stellar Astrophysics · Physics 2022-10-26 G. Livadiotis , D. J. McComas , H. O. Funsten , N. A. Schwadron , J. R. Szalay , E. Zirnstein

The first observed connection between kinetic instabilities driven by proton temperature anisotropy and estimated energy cascade rates in the turbulent solar wind is reported using measurements from the Wind spacecraft at 1 AU. We find…

We study correlations of the temperature ratio (which is an indicator for perpendicular ion heating) and the differential flow of the alpha particles with the power of transverse fluctuations that have wave numbers between 0.01 and 0.1…

Solar and Stellar Astrophysics · Physics 2011-11-14 S. Bourouaine , E. Marsch , F. M. Neubauer

Polytropic models of stellar winds remain to be useful tools because they allow for a simple description of the energy balance of the expanding plasma without explicitly specifying potentially complex energy transport processes like, e.g.,…

Solar and Stellar Astrophysics · Physics 2026-04-23 L. Westrich , B. Shergelashvili , H. Fichtner , V. N. Melnik

Context. The presence of a magnetic guide field induces several types of anisotropy in solar wind turbulence. The energy cascade rate between scales in the inertial range depends strongly on the direction of this magnetic guide field,…

Plasma Physics · Physics 2022-05-18 N. Andrés , F. Sahraoui , Huang , L. Z. Hadid , S. Galtier

The thermodynamics of interplanetary coronal mass ejections (ICMEs) is often described using a polytropic process. Estimating the polytopic index ($\gamma$) allows us to quantify the expansion or compression of the ICME plasma arising from…

Solar and Stellar Astrophysics · Physics 2025-07-24 Debesh Bhattacharjee , Saikat Majumder , Prasad Subramanian

An initial theoretical attempt to explain the observed decrease of the polytropic/adiabatic index $\gamma$ in the solar corona has been accomplished. The chemical reactions of the ionization-recombination processes in local thermodynamic…

Solar and Stellar Astrophysics · Physics 2023-12-25 Albert M. Varonov , Todor M. Mishonov

Correlations are studied between the power density of transverse waves having frequencies between $0.01$ and $1$ normalized to the proton gyrofrequency in the plasma frame and the ratio of the perpendicular and parallel temperature of the…

Solar and Stellar Astrophysics · Physics 2010-08-04 Sofiane Bourouaine , Eckart Marsch , Fritz M. Neubauer

We extend the analysis of 1211.2199, where the photon production rate of an anisotropic strongly coupled plasma with Nf<<Nc massless quarks was considered. We allow here for non-vanishing quark masses and study how these affect the spectral…

High Energy Physics - Theory · Physics 2014-01-28 Viktor Jahnke , Andres Luna , Leonardo Patino , Diego Trancanelli

Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure-anisotropy-driven instabilities such as the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Sofiane Bourouaine , Daniel Verscharen , Benjamin D. G. Chandran , Bennett A. Maruca , Justin C. Kasper

We investigate the dynamics of plasma-based acceleration processes with collisionless particle dynamics and non negligible thermal effects. We aim at assessing the applicability of fluid-like models, obtained by suitable closure assumptions…

The acceleration of the solar coronal plasma to supersonic speeds is one of the most fundamental yet unresolved problem in heliophysics. Despite the success of Parker's pioneering theory on an isothermal solar corona, the realistic solar…

Solar and Stellar Astrophysics · Physics 2022-12-21 Chen Shi , Marco Velli , Stuart D. Bale , Victor Réville , Milan Maksimović , Jean-Baptiste Dakeyo