Galaxy-halo connection in cosmology with wide spectroscopic
surveys

Speaker : Antoine Rocher EPFL, Switzerland

Abstract :

Since the early 2000s, wide spectroscopic surveys, in particular multi-fibre
experiments, have provided significant insights into the three-dimensional
distribution of galaxies and quasars in the Universe, by constraining
cosmological parameters through precise measurements of the baryon
acoustic oscillation (BAO) scale and the non-linear growth rate of structure
from redshift space distortions. Current and upcoming stage IV
spectroscopic surveys, such as the Dark Energy Spectroscopic Instrument
(DESI) or the 4-metre Multi-Object Spectrograph Telescope (4MOST) aims
to reach sub-percent precision on cosmological parameters over a broad
redshift range of 0.1 < z < 3.5.
In this talk, I will give an overview of the DESI survey and its scientific
goals. In particular, I will focus on the galaxy-halo connection, i.e. how
galaxies are connected to the underlying matter field. I will present results
obtained using the early data release of DESI to constrain the connection
between DESI galaxies (luminous red galaxies (LRGs) and Emission Line
Galaxies (ELGs)) using the halo occupation distribution (HOD) framework,
an empirical approach to link galaxies and dark matter halos in N-body
simulations.