DESI First Year Cosmological Results

par Corentin Ravoux

vendredi 24 mai 2024, 14:30 → 15:30 Europe/Paris

Amphi 9111

The energetic content of the Universe today is still unknown at 95%. The Dark Energy Spectroscopic Instrument (DESI) aims, among others, to shed light on the dark energy components (75%) that cause the accelerated expansion of the Universe. DESI is a ground-based spectrograph that will measure the spectra of 40 million galaxies and quasars at redshifts 0<z<5. This sample of galaxies is used to detect the Baryon Acoustic Oscillation (BAO) signal, a standard ruler signal originating from primordial plasma physics. Measuring this BAO signal over an extensive redshift range allows us to recover the Universe's expansion history and put strong constraints on the Hubble constant H₀, the matter's energetic content Ω_m, the dark energy properties w (and w₀/w_a), and the sum of neutrino masses Σm_ν. 

I will present the results from the analysis of the first year of DESI data, focusing particularly on its high-redshift matter tracer: the Lyman-alpha forest. I will also give a brief overview of other measurements performed by DESI using Lyman-alpha forest, such as the one-dimensional power spectrum and tomographic mapping.

 

DESI_y1_results_ravoux_lpca_seminar_may_2024.pdf