Observations of redshifted 21-cm emission of neutral hydrogen are a rapidly growing area of cosmology research.  Measurements across a wide range of radio frequencies allow us to access redshifts that encompass a vast comoving volume, spanning both cosmic dawn and the formation of large-scale structure.  I will describe two new experiments, PRIZM and HIRAX, that aim to shed new light on the universe's evolution via redshifted 21-cm measurements.  PRIZM is an experiment that is designed to study cosmic dawn by observing globally averaged 21-cm emission in a frequency range of 50-150 MHz.  The instrument consists of two modified four-square antennas and a dual-polarization spectrometer back end.  PRIZM deployed in April 2017 to Marion Island, an exceptionally isolated and radio-quiet location in the sub-Antarctic, and the first winter science observations are currently in progress.  HIRAX is an experiment that will measure baryon acoustic oscillations (BAOs) through 21-cm intensity mapping over a frequency range of 400-800 MHz.  By using the characteristic 150-Mpc BAO scale as a "ruler," HIRAX will chart the expansion history of the universe during the period when dark energy began to dominate. The HIRAX radio telescope array will be sited in South Africa and will ultimately comprise 1024 dishes, each six meters in diameter, placed in a compact configuration.  The construction of the first eight-element HIRAX prototype is currently near completion.  I will discuss the design and project status of PRIZM and HIRAX, as well as science prospects for both experiments.

Salads, sandwiches, and wraps are catered by D'Angelo Italian Market.
Bottled water will be provided.

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