Speaker
Dr
Takeo Moroi
(U. of Tokyo)
Description
I discuss a possibility to convert dark radiation to photon in the
early universe. In particular, I show that dark radiation consisting
of axion-like particles can resonantly convert into photons under the
intergalactic magnetic field. Such a conversion process can
effectively heat up the Rayleigh-Jeans tail of the CMB, which may
explain the anomaly in the 21cm spectrum recently reported by EDGES
experiment. I also discuss possibilities of the dark radiation other
than axion-like particle.
