Was there an early reionization component in our universe?

Abstract

A deep understanding of the Epoch of Reionization is still missing in our knowledge of the universe. While future probes will allow us to test the precise evolution of the free electron fraction from redshifts between $z\simeq 6$ and $z\simeq 20$, at present one could ask what kind of reionization processes are allowed by present Cosmic Microwave Background temperature and polarization measurements. An early contribution to reionization could imply a departure from the standard picture where star formation determines the reionization onset. BBy considering a broad class of possible reionization parameterizations, we find that current data do not require an early reionization component in our universe and that only one marginal class of models, based on a particular realization of reionization, may point to that. In addition, the frequentist Akaike Information Criterion (AIC) provides strong evidence against alternative reionization histories, favoring the most simple reionization scenario, which describes reionization by means of only one (constant) reionization optical depth $\tau$.

16 pages, 3 figures. Version accepted for publication in JCAP

References in corpus (24)

• The James Webb Space Telescope
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Cosmic microwave background limits on accreting primordial black holes
• Evidence of patchy hydrogen reionization from an extreme Ly$\alpha$ trough below redshift six
• Effect of Primordial Black Holes on the Cosmic Microwave Background and Cosmological Parameter Estimates
• CMB bounds on disk-accreting massive Primordial Black Holes
• Line Emitting Galaxies Beyond a Redshift of 7: An Improved Method for Estimating the Evolving Neutrality of the Intergalactic Medium
• New observations of z~7 galaxies: evidence for a patchy reionization
• Rapid Decline of Lyman-alpha Emission Toward the Reionization Era
• Impact of dark matter decays and annihilations on reionization
• Constraints on Dark Matter annihilations from reionization and heating of the intergalactic gas
• CMB polarization features from inflation versus reionization
• Gamma-ray Burst Cosmology
• The Cosmic Microwave Background and the Ionization History of the Universe
• How Dark Matter Reionized The Universe
• Reionization constraints from five-year WMAP data
• Warm Dark Matter and Cosmic Reionization
• Impact of reionization on CMB polarization tests of slow-roll inflation
• Witnessing the reionization history using Cosmic Microwave Background observation from Planck
• Harrison-Z'eldovich primordial spectrum is consistent with observations
• Impact of general reionization scenarios on extraction of inflationary parameters
• Evidence for horizon-scale power from CMB polarization
• Light Sterile Neutrinos and Inflationary Freedom
• Robustness of cosmological axion mass limits

Cited by in corpus (10)

• The Cosmological Evolution of Light Dark Photon Dark Matter
• Dark Photon Dark Matter in the Presence of Inhomogeneous Structure
• Cosmic Microwave Background Constraints in Light of Priors Over Reionization Histories
• Is the Harrison-Zel'dovich spectrum coming back? ACT preference for $n_s\sim 1$ and its discordance with Planck
• Does Planck 2015 polarization favor high redshift reionization?
• A novel CMB polarization likelihood package for large angular scales built from combined WMAP and Planck LFI legacy maps
• Joining bits and pieces of reionization history
• Reionization in the dark and the light from Cosmic Microwave Background
• A Semiblind Reconstruction of the History of Effective Number of Neutrinos Using CMB Data
• Galactic magnetic fields seeded by ultralight dark photons