• Physics and Astronomy Colloquium

February 7, 2025 3:30 PM - February 7, 2025 4:30 PM
PAIS 1100

Host:

Greg Taylor

Presenter:

Dr. Daniel Jacobs (ASU)

Video recording

The redshifted 21 cm hydrogen line is a probe of large scale structure which could be used to answer questions about fundamental physics, cosmology, and astrophysics. Unobscured by absorption emission, the 21cm line is visible before the first stars until recent times. For example it is predicted to be strongly visible near redshift 20 when the first stars and black holes competed with exotic physics for primacy in a dense, nearly linear, universe. Motivated by this promise several experimental telescopes have been built and much has been learned about the experimental challenges. Today, the Hydrogen Epoch of Reionization Array is the largest such operating array and has been observing for over eight years. As HERA observations have continued, new analyses applied to the ever-growing dataset are delivering results with increasing sensitivity. Meanwhile these analyses also suggest new approaches for the next generation of instruments to answer new questions about galaxy formation raised by JWST and long standing mysteries about the scale of fluctuations seeded by inflation, neutrino mass, and more.