Unraveling the Universe with DESI
  The Dark Energy Spectroscopic Instrument (DESI) is a stage IV ground-based
dark energy experiment planned to begin operations in 2020. In this article, we
provided a short review of DESI presented during the conference {\it Recontres
de Moriond 2018}. DESI will use four different tracers for mapping the
universe: from redshift 0.05 up to redshift 1.7 with galaxies and from 2.1 to
3.5 using quasars. DESI will measure a total of 35 million spectra covering
regions of universe never explored before, providing a map of large scale
structure that will enable major advances in the investigation of cosmic
acceleration. The key science goals for DESI are to constrain dark energy and
potential deviations of General Relativity using two complementary observables:
the Baryonic Acoustic Oscillations (BAO) and the Redshift Space Distortions
(RSD). Additional science goals, such as constraining the sum of neutrino
masses and inflation, are expected with the baseline project. DESI installation
started on February 2018 and the current construction of the instrument is on
track. The imaging surveys that will serve to determine the targets are
currently in the final stages, having achieved 80\% completion, and are
expected to be finalized by the end of 2018. The DESI Collaboration is actively
preparing for survey operations and science analysis, to be ready for the first
light in January 2020.
