Colloquium on Dec. 8, 2022

Signatures of excess radio background on reionization 21cm signal

Speaker: Junsong Cang (IHEP,CAS)

Venue: SWIFAR Building 2111

Time: 16:00 PM, Thursday, Dec. 8, 2022

Abstract:

The 21cm signal from neutral hydrogen is currently our only probe of the cosmic dark ages, the first reionisation 21cm signal was reported by the EDGES experiment in 2018, but the abnormal depth and profile of this signal presents a challenge for the standard cosmology. In this talk, I will show that the radio emissions from first galaxies and primordial black holes can potentially explain both the depth and the profile of the EDGES signal. The inhomogeneous distribution of these radio sources can also leave footprints on 21cm power spectra and be probed by experiments such as SKA and HERA.