The EDGES cosmology experiment aims to measure the sky-average signal emitted by neutral hydrogen before the first billion years of the Universe. This yet undetected signal will carry a wealth of information about the physics of the early intergalactic medium, and the formation and evolution of the first stars, black holes, and galaxies. The signal also has the potential to constrain properties of dark matter as well as to estimate the impact of dark matter on this transformational period of the Universe.
The hydrogen signal was emitted originally at 1.41 GHz but has been redshifted to frequencies below 200 MHz due to cosmic expansion. EDGES observes in the frequency range 50-200 MHz using two single-antenna total power radiometers. The instruments are located in the desert of Western Australia due to its clean radio environment with low artificial interference. The current generation of EDGES instruments has achieved the lowest systematic uncertainties reported to date for this type of measurement and, consequently, the best data quality for science analyses. This has allowed to start probing realistic cosmological models.
This talk will describe the EDGES experiment and present preliminary results of the data analysis. In addition the talk will discuss the scientific potential of the DARE space mission (soon to be proposed to NASA), which will conduct these cosmological observations from the Lunar far side. This location not only eliminates the impact of the Earth's ionosphere on the measurements, but also offers the cleanest radio environment, free of interference, in the inner Solar System. DARE will capitalize on the lessons learned by EDGES from ground-based observations and will incorporate key novel features in order to conduct precision cosmology from space and shed light on one of the least understood epochs of the Universe.