6533b86dfe1ef96bd12cab2f

RESEARCH PRODUCT

Current constraints on early and stressed dark energy models and future 21 cm perspectives

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Despite the great progress of current cosmological measurements, the nature of the dominant component of the universe, coined dark energy, is still an open question. Early Dark Energy is a possible candidate which may also alleviate some fine tuning issues of the standard paradigm. Using the latest available cosmological data, we find that the 95% CL upper bound on the early dark energy density parameter is $\Omega_{\textrm{eDE}}$. On the other hand, the dark energy component may be a stressed and inhomogeneous fluid. If this is the case, the effective sound speed and the viscosity parameters are unconstrained by current data. Future omniscope-like $21$cm surveys, combined with present CMB data, could be able to distinguish between standard quintessence scenarios from other possible models with $2\sigma$ significance, assuming a non-negligible early dark energy contribution. The precision achieved on the $\Omega_{\textrm{eDE}}$ parameter from these $21$ cm probes could be below $\mathcal{O} (10\%)$.