Abstract
The 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
∼(
m
W
/
m
e
)
4
(B/
B
c
)
2
. The energy-loss rate due to the process
γγ→ν
ν
¯
in magnetic field is obtained.