From the precision era towards the accuracy era of cosmology with DESI

The Dark Energy Spectroscopic Instrument (DESI) located at Kitt Peak National Observatory's 4m Mayall telescope is creating the largest map of galaxies and quasars ever obtained, probing the large-scale structure evolution of the universe with unprecedented precision. DESI recently released its first cosmological results based on the baryon acoustic oscillation (BAO) signal that serves as a standard ruler mapping the expansion history of the universe with unprecedented precision. And there is more to be released very soon: the DESI redshift-space distortion (RSD) and the full-shape measurements probing the structure growth history, again, with unprecedented precision.
But how do we make sure the measurements are not only precise but also as accurate as possible? In addition to the systematic uncertainties summarised in this blogpost (1) I wrote that needs to be carefully accounted for, DESI incorporated the catalogue-levelBlinding scheme I developed in 2006.10857 (2) to avoid confirmation bias. Furthermore, the DESI full-shape analysis makes use of theShapeFit methodology I developed in 2106.07641 (3) ensuring robust extraction of signals in the galaxy clustering statistics of different physical origins (BAO, RSD, Shape) in a nearly model-independent way. As such, it complements the model-dependent full-shape fits to clustering: the interplay between both approaches allows us to find cracks in the model or identify potential unknown systematic uncertainties.
In this talk, after introducing what DESI actually measures, I provide an overview of the published DESI cosmology results explaining the contribution of my PhD thesis work detailed above, and close with an outlook of the DESI cosmological analysis beyond two-point statistics I am working on at the moment.

(1) https://www.desi.lbl.gov/2024/06/11/desi-2024-supporting-papers-june-11-guide/
(2) https://arxiv.org/abs/2006.10857
(3) https://arxiv.org/abs/2106.07641