The Optimal Cosmic Epoch for Precision Cosmology

Abstract

The statistical uncertainty in measuring the primordial density perturbations on a given comoving scale is dictated by the number of independent regions of that scale that are accessible to an observer. This number varies with cosmic time and diminishes per Hubble volume in the distant past or future of the standard cosmological model. We show that the best constraints on the initial power spectrum of linear density perturbations are accessible (e.g. through 21-cm intensity mapping) at redshifts z~10, and that the ability to constrain the cosmological initial conditions will deteriorate quickly in our cosmic future.

4 pages, 4 figures, Accepted for Publication in the Journal of Cosmology and AstroParticle Physics (JCAP)

References in corpus (3)

• How accurately can 21 cm tomography constrain cosmology?
• Evolution of the 21 cm signal throughout cosmic history
• Possibility of Precise Measurement of the Cosmological Power Spectrum With a Dedicated 21cm Survey After Reionization

Cited by in corpus (5)

• The information content of cosmic microwave background anisotropies
• Cosmological Information Contents on the Light-Cone
• Testing the scale-dependent hemispherical asymmetry with the 21-cm power spectrum from the epoch of reionization
• How much cosmological information can be measured?
• How bright was the Big Bang?