Various 21 cm signals from neutral hydrogen have been proposed to probe the cosmic dawn, including the global 21 cm spectrum, the 21 cm tomography, and the 21 cm forest. They will provide valuable insights into the early structure formation during the cosmic dawn, and have been identified as the key scientific goals for a number of ground-based and space-borne radio experiments, including the international Square Kilometre Array and the Hongmeng project. In this talk, I’ll share some of the recent progresses on the theories and experiments for probing the cosmic dawn. I will also introduce the Hongmeng project, which is going to measure the global 21 cm signal on lunar orbit.

BIO

Yidong Xu got her PhD from Peking University in 2011, and is now an associate research professor at the National Astronomical Observatories, Chinese Academy of Sciences. She mainly works on cosmic dawn and reionization, and 21 cm cosmology. She is a member of the Hongmeng collaboration, and also a member of both the SKA CD/EoR Science Working Group and the SKA Cosmology Science Working Group.