Speaker
Description
Early Dark Energy (EDE) contributing a fraction f_EDE(z_c) ∼ 10% of the energy density of the universe around z_c = 3500 and diluting as or faster than radiation afterwards, can provide a simple resolution to the Hubble tension, the ∼ 5σ discrepancy – in the ΛCDM context – between the H0 value derived from early- and late-universe observations. However, the inclusion of Large-Scale Structure (LSS) data, which are in ∼ 3σ tension with both ΛCDM and EDE cosmologies, might break some parameter degeneracy and alter these conclusions.
I will discuss the viability of the EDE scenario in view of a host of high- and low-redshift measurements, including LSS observations from recent weak lensing surveys, CMB, Baryon Acoustic Oscillation (BAO), growth function and Supernova Ia (SNIa) data, as well as the full-shape galaxy power spectrum from BOSS/SDSS, analyzed using the effective field theory (EFT) of LSS. I will show that the EDE cosmology still provides a potential resolution to the Hubble tension when confronted against current LSS data, though upcoming spectroscopic galaxy surveys, such as Euclid and DESI, will put it under stringent new tests. Finally, I will reassess the EDE scenario in light of the CMB lensing anomalies in Planck data, and I will outline further theoretical extensions that could allow to fully restore cosmological concordance.
