Implications for dark energy and cosmology from recent DES and DESI results
por
Sr.Nicola Deiosso(CIEMAT), Dr.Santiago Ávila(CIEMAT)
→
UTC
Maria de Maeztu
Maria de Maeztu
Descripción
Implications of Cosmological Expansion Models from the Final Dark Energy Survey BAO and SN Data
Speaker: Santiago Ávila (CIEMAT)
The Dark Energy Survey (DES) recently released the final results of its two principal probes of the expansion history: Type Ia Supernovae (SN) and Baryonic Acoustic Oscillations (BAO). In this work, we explore the cosmological implications of these data in combination with external Cosmic Microwave Background (CMB), Big Bang Nucleosynthesis (BBN), and age-of-the-Universe information. The BAO measurement, which is ∼2σ away from Planck-ΛCDM predictions, pushes for low values of Ωm compared to Planck in contrast to SN which prefers a higher value. We identify several tensions among datasets in the ΛCDM model that cannot be resolved by including either curvature or a constant dark energy equation of state.
In w0waCDM, the tensions are alleviated and we find a 3.2σ deviation from ΛCDM for DES BAO and SN in combination with Planck. For the combination of all the background cosmological probes considered (including θ* from Planck), we still find a deviation of 2.8σ from ΛCDM. This work provides further evidence for non-ΛCDM physics or systematics, which is consistent with recent claims in support of evolving dark energy.
Measurements of Baryon Acoustic Oscillations and Cosmological Constraints From DESI DR2
Speaker: Nicola Deiosso (CIEMAT)
Abstract: The Dark Energy Spectroscopic Instrument (DESI) is leading a groundbreaking five-year survey to investigate the influence of dark energy on cosmic expansion and the evolution of large-scale structure. Latest baryon acoustic oscillations (BAO) measurements and cosmological results from DESI will be presented and discussed, based on three years of observations, with tens of millions of spectra collected. We considered both solely the data from the survey and in combination with cosmic microwave background (CMB), supernovae (SNe), Big Bang Nucleosynthesis (BBN) priors, and 3x2pt measurements observations, as well as being compared with the results obtained with the previous DESI BAO dataset (DR1). In this analysis, we focused on the measurement of constraints on expansion rate, with particular attention on the comparison with Planck results considering ΛCDM model, on dark energy equation of state and on finding upper limits for the sum of neutrino masses. These results provide a critical assessment of the standard cosmological model.