Jul 15 – 19, 2024
Perimeter Institute for Theoretical Physics
America/Toronto timezone

Cosmological implications from DESI Y1 BAO and Future Forecasts

Jul 17, 2024, 3:15 PM
15m
PI/1-100 - Theatre (Perimeter Institute for Theoretical Physics)

PI/1-100 - Theatre

Perimeter Institute for Theoretical Physics

190
Contributed Talk Contributed Talks

Speaker

Hanyu Zhang

Description

We present key cosmological findings from the Dark Energy Spectroscopic Instrument (DESI)’s first year baryon acoustic oscillations (BAO) measurements. DESI's BAO provide robust measurements of the transverse comoving distance and Hubble rate across seven redshift bins, spanning a redshift range of 0.1 < z < 4.2. DESI BAO data alone align well with the flat ΛCDM model with Ωm=0.295±0.015. Paired with a baryon density prior from Big Bang Nucleosynthesis and the acoustic angular scale from the cosmic microwave background (CMB) data, we find H0=68.52±0.62 km/s/Mpc. Combined analyses with CMB anisotropies and lensing from Planck and ACT yield Ωm=0.307±0.005 and H0=67.97±0.38 km/s/Mpc. Extending the baseline model with a constant dark energy equation of state parameter, w, results in w=−0.99+0.15−0.13. In a dark energy model with time-varying equation of state parametrized by w0 and wa, combined with various supernovae data, indicate deviations from ΛCDM at significance levels up to 3.9σ. For flat ΛCDM with the sum of neutrino mass free, DESI and CMB establish an upper limit of ∑ mν <0.072 (0.113) at 95% confidence for a ∑mν>0 (0.059) eV prior. We will also show forecasts for Y3 and Y5 results as well as prospects with DESI II.

arXiv reference, if applicable: https://arxiv.org/abs/2404.03002
Contact Email [email protected]

Primary author

DESI Collaboration

Co-author

Hanyu Zhang

Presentation materials

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External references