2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/149082The low-energy two neutrino-two photon interactions in the presence of homogeneous magnetic field are studied. The cross sections in external magnetic field are shown to be larger than in vacuum by factor $\sim (m_W /m_e) ^4(B/B_c) ^2$. The energy-loss rate due to the process $γγ\to ν\barν$ in magnetic field is obtained.5 pages, published versionHigh Energy Physics - PhenomenologyAstrophysicstext