2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45293The radiative decay of the massive neutrino $ν_i \rightarrow ν_j γ( m_i > m_j )$ in the external electromagnetic field is analyzed in detail in the framework of the standard model with lepton mixing. It is shown, that a sort of a catalysis of the neutrino radiative decay takes place. The effect of catalysis is significant in the strong electromagnetic fields ($F \gg B_e = m^2_e / e \simeq 4.41 \cdot 10^{13}$ G) ; it is more pronounced in the case of the decay of the ultrarelativistic neutrino $(E_ν \gg m_ν)$, even in a relatively weak electromagnetic field ($F \ll m^2_e/e$).(talk given at the VIII International Seminar "Quarks-94", Vladimir, Russia, May 11-18, 1994), 12 pages, LaTeX (uses world_sci.sty, and lnpi.sty file appended), Yaroslavl, Yaroslavl State University preprint YARU-HE-94/04High Energy Physics - Phenomenologytext