EDGES disfavors excess radio background and interacting dark matter
Info:
| Author | Junsong Cang 博士后 |
|---|---|
| Affiliation | Scuola Normale Superiore and SlSSA |
| Time | 2025-08-20 10:00 |
| Location | 仙林园区3-402室 |
| Presentation materials | Download |
报告摘要:
The first global 21cm signal reported by EDGES featured an absorption trough centered around redshift 17 with a depth of -500 mK, such deep signal can be achieved by either an excess radio background or cooling induced by interactions between dark matter and baryon. We re-analysed the EDGES sky temperature data with physically motivated cosmic 21cm signal models driven by either interacting dark matter or excess radio background from Pop III galaxies, we jointly forward modelled the foreground contamination and experimental calibration residuals. Opposite to the initial EDGES claim, our result shows that for excess radio background model, the posteriors for 21cm brightness temperature obtained with EDGES data remain entirely consistent with the standard model. Our preliminary analysis with interacting dark matter also points to similar results. Future experiments like Hongmeng can further constrain global 21cm signal evolution and potentially give extremely stringent constraints on interacting dark matter and early radio galaxies.
报告人简介:
Junsong Cang is a postdoctoral fellow at Scuola Normale Superiore and SlSSA in Italy (2024-2028, under joint supervision of Prof Andrei Mesinger and Roberto Trotta). He received his PhD in 2023 from the Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, working on the searches for dark matter and primordial black holes using CMB, 21cm and gravitational wave. He now mainly works on 21cm cosmology and the epoch of reionization, his recent and ongoing research projects include data analysis with SKA and EDGES, development of 21cmFAST simulation tool.