We review the current state of the kinetic theory of acceleration and propagation of energetic (thermal and nonthermal) electrons during solar flares. The classical models of a thick target, together with their extension to models that take the reverse current effect and the acceleration of electrons in collapsing magnetic traps into account, are discussed in detail. Analytic solutions of the corresponding kinetic equations are found and used to calculate the characteristics of the hard X-ray bremsstrahlung generated by energetic electrons. The results obtained are compared with modern high-precision data from satellite observations of solar flares. The radiation polarization degree is calculated and the prospects for its measurement in future space experiments are discussed.

Keywords: Sun, solar flares, electron acceleration, kinetic equation, collision integral, bremsstrahlung, polarization PACS: 96.60.−j, 96.60.Iv, 96.60.qe, 96.60.Tf (all) DOI: 10.3367/UFNe.2021.08.039048 URL: https://ufn.ru/en/articles/2023/5/a/ 001112604700001 2-s2.0-85182884076 2023PhyU...66..437G Citation: Gritsyk P A, Somov B V "Modern analytic models of acceleration and propagation of electrons in solar flares" Phys. Usp. 66 437–459 (2023) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 28th, July 2021, revised: 20th, August 2021, accepted: 27th, August 2021 Оригинал: Грицык П А, Сомов Б В «Современные аналитические модели ускорения и распространения электронов в солнечных вспышках» УФН 193 465–490 (2023); DOI: 10.3367/UFNr.2021.08.039048