Redshift remapping and cosmic acceleration in dark-matter-dominated cosmological models

DOI: 
10.1093/mnras/stx1550
Publication date: 
01/10/2017
Main author: 
Wojtak, Radosław
IAA authors: 
Prada, Francisco
Authors: 
Wojtak, Radosław;Prada, Francisco
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Volume: 
470
Pages: 
4493-4511
Abstract: 

The standard relation between the cosmological redshift and cosmic scalefactor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the Λ cold-dark-matter (ΛCDM) cosmological model. This relation is not a fundamental theory and thus observational determination of this function (redshift remapping) should be regarded as an insightful alternative to holding its standard form in analyses of cosmological data. Here we present non-parametric reconstructions of redshift remapping in dark-matter-dominated models and constraints on cosmological parameters from a joint analysis of all primary cosmological probes including the local measurement of the Hubble constant, Type Ia supernovae, baryon acoustic oscillations (BAO), Planck observations of the cosmic microwave background (CMB) radiation (temperature power spectrum) and cosmic chronometers. The reconstructed redshift remapping points to an additional boost of redshift operating in late epoch of cosmic evolution, but affecting both low-redshift observations and the CMB. The model predicts a significant difference between the actual Hubble constant, h = 0.48 ± 0.02, and its local determination, h<SUB>obs</SUB> = 0.73 ± 0.02. The ratio of these two values coincides closely with the maximum expansion rate inside voids formed in the corresponding open cosmological model with Ω<SUB>m</SUB> = 0.87 ± 0.03, whereas the actual value of the Hubble constant implies the age of the Universe that is compatible with the Planck ΛCDM cosmology. The model with redshift remapping provides excellent fits to all data and eliminates recently reported tensions between the PlanckΛCDM cosmology, the local determination of the Hubble constant and the BAO measurements from the Ly α forest of high-redshift quasars.

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037095331&doi=10.1093%2fmnras%2fstx1550&partnerID=40&md5=4bda0a4400f3398633d623d80a351a36
ADS Bibcode: 
2017MNRAS.470.4493W
Keywords: 
methods: statistical;cosmological parameters;distance scale;cosmology: observations;Astrophysics - Cosmology and Nongalactic Astrophysics