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RESEARCH PRODUCT
Was there an early reionization component in our universe?
Olga MenaNickolay Y. GnedinNickolay Y. GnedinStefano GariazzoPablo Villanueva-domingosubject
PhysicsCosmology and Nongalactic Astrophysics (astro-ph.CO)010308 nuclear & particles physicsStar formationComponent (thermodynamics)media_common.quotation_subjectCosmic microwave backgroundAstrophysics::Instrumentation and Methods for AstrophysicsFOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics16. Peace & justice01 natural sciencesRedshiftUniverseFrequentist inference0103 physical sciencesOptical depth (astrophysics)010303 astronomy & astrophysicsReionizationAstrophysics - Cosmology and Nongalactic Astrophysicsmedia_commondescription
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 $\tau$.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-12-07 | Journal of Cosmology and Astroparticle Physics |