DESI Focal Plate Alignment and Galaxy Biases in BAO Measurements
This event is part of the Departmental Seminars.
• Steve Ahlen (1st reader) • Martin Schmaltz (2nd reader) • Alex Sushkov (committee chair) • Edward Kearns • Daniel Eisenstein
Abstract: The baryon acoustic oscillation (BAO) feature in the clustering of matter is a powerful tool to study large-scale structures of the universe. The Dark Energy Spectroscopic Instrument (DESI) will use BAO as a standard ruler to map the expansion history of the universe and constrain cosmological parameters. BU has played a significant role in the manufacturing and integration of DESI focal plate structure, and is contributing to understanding systematic uncertainties in the modelling and fitting methods with state-of-the-art cosmological N-body simulations. After a brief overview of the instrument and its science background, I will present the metrology-based approach to evaluating and aligning DESI focal plate structure with complete results included, as well as our ongoing investigation into how galaxy biases in the observed galaxy distribution, such as assembly bias and velocity bias, may shift the BAO measurements.