Radiation in equilibrium with plasma and plasma effects on cosmic microwave background

Abstract

The spectrum of the radiation of a body in equilibrium is given by Planck's law. In plasma, however, waves below the plasma frequency cannot propagate; consequently, the equilibrium radiation inside plasma is necessarily different from the Planck spectrum. We derive, using three different approaches, the spectrum for the equilibrium radiation inside plasma. We show that, while plasma effects cannot be realistically detected with technology available in the near future, there are a number of quantifiable ways in which plasma affects cosmic microwave background (CMB) radiation.

Equilibrium radiation in a plasma medium with spatial and frequency dispersion

“…It is worth noting, that much attention was paid to the study of the optical properties of various plasma systems [5][6][7][8], but not to the SEDER investigation. The SEDER in the substance which is in thermodynamic equilibrium with radiation, is considered much less frequently (see [9][10][11][12][13][14][15][16][17][18][19] and references therein). In the presence of a substance, the corresponding result differs from the Planck distribution, which corresponds to an ideal photon gas [2].…”

“…The main efforts for the last two decades have been devoted to the problem of accounting for the spatial dispersion of the properties of plasma medium (along with the frequency dispersion) in the SEDER modification [9,16,17]. The solution of this problem is essential, in particular, for astrophysical applications [12,18], where the role of spatial dispersion in the dielectric permittivity (DP) is especially essential for the relativistic case [20]. However, the general solution of this problem is still absent and various approaches lead to different results.…”

Magnetogenesis by Wave-Driven Momentum Exchange

“…Various mechanisms have been proposed as origins of these seed fields, from the Weibel instability (Schlickeiser & Shukla 2003), to currents from charged cosmic rays (Miniati & Bell 2011;Ohira 2020), to expulsion by jets from magnetized compact objects (Daly & Loeb 1990), to photon pressure on charged particles (Munirov & Fisch 2019). However, the dominant favored mechanism in most scenarios (Zweibel 2013;Kulsrud et al 1997;Gnedin et al 2000;Hanayama et al 2005;Hanayama & Tomisaka 2006;Naoz & Narayan 2013) is the Biermann battery (Schlüter & Biermann 1950).…”

Высокочастотная Асимптотика Одного Интеграла В Теории Равновесного Излучения Электронного Газа

“…Кроме того, имеющиеся экспериментальные данные [8,9] свидетельствуют о влиянии вещества на характеристики собственного излучения однородной и изотропной материальной среды. Различные аспекты определения характеристик равновесного электромагнитного излучения при наличии вещества рассмотрены в работах [10][11][12][13] и цитированной там литературе. В частности, в работе [10] было установлено, что средняя энергия равновесного излучения E ph в материальной среде, занимающей макроскопический объем V , может быть представлена в виде…”