New physics from a precision concordance model of the radio sky

My proposal is to build an unprecedentedly accurate and complete model of the radio sky, and then use it to solve several important problems in astrophysics and cosmology. The model will incorporate improved analyses of existing data, plus new, precisely-calibrated observations from a novel horn antenna telescope that I will build. Using advanced statistical techniques capable of handling millions of parameters – implemented in my world-leading Hydra code – I will disentangle the many physical components of the sky, along with troublesome instrumental effects that have clouded our view until now. This will transform radio cosmology by removing some of the most important limitations of experiments like the Hydrogen Epoch of Reionization Array (HERA) and Square Kilometre Array (SKAO), which seek to observe signals from neutral hydrogen (the 21cm line) around the first stars and galaxies. It will also directly address two major observational anomalies – the ARCADE-2 excess and EDGES absorption feature – that may be the first signs of new physics. The result will be a unique “concordance” model of the radio sky that connects our understanding of radio emission all the way from the early Universe to the present day.This groundbreaking model will include new data from HERA and the MeerKAT Large Area Synoptic Survey, which are the most sensitive surveys of their kind. It will also include detailed corrective modelling of instrumental effects in widely-used datasets such as the Haslam 408 MHz map. My novel horn antenna will provide a new and much-needed “absolute” calibration reference, as well as directly observing the sky-averaged 21cm signal, a crucial ingredient in understanding early galaxy formation. The major outcomes will be best-ever measurements of Galactic synchrotron physics, the cosmic radio background, and the sky-averaged 21cm line, plus vital new constraints on Cosmic Dawn and dark energy from 21cm fluctuations at high and low redshift respectively.