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The damping of a massless fermion coupled to a massless scalar particle at finite temperature is considered using the Braaten-Pisarski resummation technique. First the hard thermal loop diagrams of this theory are extracted and effective…

High Energy Physics - Phenomenology · Physics 2009-10-28 Markus H. Thoma

Electron evaporation plays an important role in the electron temperature evolution and thus expansion rate in low-density ultracold plasmas. In addition, evaporation is useful as a potential tool for obtaining colder electron temperatures…

Plasma Physics · Physics 2017-06-07 Craig Witte , Jacob L. Roberts

We construct a solution of a pure conduction problem in ice and bedrock. This solution is suitable for, and is used in this paper for, verifying a numerical scheme for conservation of energy. This exact solution forms one of a suite of…

Geophysics · Physics 2007-10-09 Ed Bueler

A simple and popular Bridgman's formula predicts a linear correlation between the thermal conductivity coefficient and the sound velocity of dense liquids. Unfortunately, it cannot be applied to strongly coupled plasma-related fluids,…

Plasma Physics · Physics 2024-09-25 Sergey Khrapak , Alexey Khrapak

The rate for the production of a pair of massive fermions in $e^+ e^-$ annihilation plus real or virtual radiation of a pair of massless fermions is calculated analytically. The contributions for real and virtual radiation are displayed…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. H. Hoang , J. H. Kühn , T. Teubner

A universal method of strictly calculating self-consistent fields of realistic plasma particles could be strictly derived from three basic tools in theoretical plasma physics: particle simulation, Vlasov-Maxwell theory and fluid theory.

Plasma Physics · Physics 2010-08-17 H. Lin

We approximate boson thermodynamic integrals as polynomials in two variables chosen to give the correct limiting expansions and to smoothly interpolate into other regimes. With 10 free parameters, an accuracy of better than 0.009\% is…

Nuclear Theory · Physics 2009-10-30 S. M. Johns , P. J. Ellis , J. M. Lattimer

We discuss the gamma-ray signal to be expected from dark matter (DM)annihilations at the Galactic Center. To describe the DM distribution in the Galactic halo we base on the Jeans equation for self-gravitating, anisotropic equilibria. In…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Lapi , A. Paggi , A. Cavaliere , A. Lionetto , A. Morselli , V. Vitale

We present a simple model to describe the dark matter density, the gas density, and the gas temperature profiles of galaxy clusters. Analytical expressions for these quantities are given in terms of only five free parameters with a clear…

Astrophysics · Physics 2009-11-13 Y. Ascasibar , J. M. Diego

We derive new approximations for quintessence solutions that are simpler and an order of magnitude more accurate than anything available in the literature, which from an observational perspective \emph{makes numerical calculations…

General Relativity and Quantum Cosmology · Physics 2025-05-06 Artur Alho , Claes Uggla

Using 14 years of Fermi-LAT data and 10 years of H.E.S.S. observations in the direction of the galactic center, we derive limits on gamma-ray lines originated from dark matter annihilations for fermionic and scalar fields. We describe the…

High Energy Physics - Phenomenology · Physics 2026-03-10 Lucia Angel , Guillermo Gambini , Leticia Guedes , Farinaldo S. Queiroz , Vitor de Souza

The helium I line intensity ratio (LIR) method is used to measure the electron density ($n_e$) and temperature ($T_e$) of fusion-relevant plasmas. Although the collisional-radiative model (CRM) has been used to predict $n_e$ and $T_e$,…

Plasma Physics · Physics 2025-06-26 Shin Kajita

Theoretical framework for power dissipation in low temperature plasmas in corona equilibrium is developed. The framework is based on fundamental conservation laws and reaction cross sections and is only weakly sensitive to plasma…

Plasma Physics · Physics 2015-10-23 J. Komppula , O. Tarvainen

We study the finite-temperature thermodynamics of a unitary Fermi gas. The chemical potential, energy density and entropy are given analytically with the quasi-linear approximation. The ground state energy agrees with previous theoretical…

Quantum Gases · Physics 2009-04-24 Fang Qin , Ji-sheng Chen

In this article we report the release of a new program for calculating the emissivity of atomic transitions. The program, which can be obtained with its documentation from our website www.scienceware.net, passed various rigorous tests and…

Atomic Physics · Physics 2010-05-12 Taha Sochi

The effects of dissipation on the thermodynamic properties of nonlinear quantum systems are approached by the path-integral method in order to construct approximate classical-like formulas for evaluating thermal averages of thermodynamic…

Statistical Mechanics · Physics 2016-11-23 Alessandro Cuccoli , Andrea Fubini , Valerio Tognetti , Ruggero Vaia

A method to determine the polarization direction of a very high energy (50 MeV - 30 GeV), linearly polarized gamma ray is analyzed and discussed. We study the differential cross section for pair production and show that the only relevant…

Astrophysics · Physics 2011-05-23 Gerardo O. Depaola , Carlos N. Kozameh , Manuel H. Tiglio

A simple model and method is proposed here to determine argon metastable number densities and electron temperature with the assumption of a Maxwell-Boltzmann electron energy distribution. This method is based on the availability of…

Plasma Physics · Physics 2010-03-16 Davide Mariotti , Yoshiki Shimizu , Takeshi Sasaki , Naoto Koshizaki

The electron-positron annihilation spectrum observed by SPI/INTEGRAL during deep Galactic Center region exposure is reported. The line energy (510.954$\pm$0.075 keV) is consistent with the unshifted annihilation line. The width of the…

Astrophysics · Physics 2009-11-10 E. Churazov , R. Sunyaev , S. Sazonov , M. Revnivtsev , D. Varshalovich

The expression for the Debye shielding in plasma physics is usually derived under the assumptions that the plasma particles are weakly coupled, so their kinetic energy is much larger than the potential energy between them, and that the…

Plasma Physics · Physics 2016-12-30 M. A. Martínez-Fuentes , J. J. E. Herrera-Velázquez