Abstract
A constant early dark energy (EDE) component contributing a fraction fEDE(zc)∼10% of the energy density of the universe around zc≃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, it has been pointed out that including Large-Scale Structure (LSS) data, which are in ∼3σ tension with ΛCDM and EDE cosmologies, might break some parameter degeneracy and alter these conclusions. We reassess the viability of the EDE against a host of high- and low-redshift measurements, by combining LSS observations from recent weak lensing (WL) surveys with CMB, baryon acoustic oscillation (BAO), growth function (FS) and Supernova Ia (SNIa) data. Introducing a model whose only parameter is fEDE(zc), we report in agreement with past work a ∼2σ preference for nonzero fEDE(zc) from Planck CMB data alone, while the tension with the local H0 measurement from sh0es is reduced below 2σ. Adding BAO, FS and SNIa does not affect this conclusion, while the inclusion of a prior on H0 from sh0es increase the preference for EDE over ΛCDM to the ∼3.6σ level. After checking the EDE nonlinear matter power spectrum as predicted by standard semi-analytical algorithms via a dedicated set of N-body simulations, we test the 1-parameter EDE cosmology against WL data. We find that it does not significantly worsen the fit to the S8 measurement as compared to ΛCDM, and that current WL observations do not exclude the EDE resolution to the Hubble tension. We also caution against the interpretation of constraints obtained from combining statistically inconsistent datasets within the ΛCDM cosmology. In light of the CMB lensing anomalies, we show that the lensing-marginalized CMB data also favor nonzero fEDE(zc) at ∼2σ, predicts H0 in 1.4σ agreement with sh0es and S8 in 1.5σ and 0.8σ agreement with kids-viking and des respectively. There still exists however a ∼2.5σ tension with the joint results from kids-viking and des. With an eye on Occam’s razor, we finally discuss promising extensions of the EDE cosmology that could allow us to fully restore cosmological concordance.