TY - JOUR
T1 - A comparison of the Rh = ct and ΛCDM cosmologies using the cosmic distance duality relation
AU - Melia, Fulvio
N1 - Funding Information:
I am grateful to the anonymous referee for suggesting several improvements to this manuscript. I am also grateful to Amherst College for its support through a John Woodruff Simpson Lectureship, and to Purple Mountain Observatory in Nanjing, China, for its hospitality while part of this work was being carried out. This work was partially supported by grant 2012T1J0011 from The Chinese Academy of Sciences Visiting Professorships for Senior International Scientists, and grant GDJ20120491013 from the Chinese State Administration of Foreign Experts Affairs
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - The cosmic distance duality (CDD) relation (based on the Etherington reciprocity theorem) plays a crucial role in awide assortment of cosmological measurements. Attempts at confirming it observationally have met with mixed results, though the general consensus appears to be that the data do support its existence in nature. A common limitation with past approaches has been their reliance on a specific cosmological model, or on measurements of the luminosity distance to Type Ia SNe, which introduces a dependence on the presumed cosmology in spite of beliefs to the contrary. Confirming that the CDD is actually realized in nature is crucial because its violation would require exotic new physics. In this paper, we study the CDD using the observed angular size of compact quasar cores and aGaussian Process reconstruction of the HII galaxy Hubble diagram - without pre-assuming any particular background cosmology. In so doing, we confirm at a very high level of confidence that the angular-diameter and luminosity distances do indeed satisfy the CDD. We then demonstrate the potential power of this result by utilizing it in a comparative test of two competing cosmological models - the Rh = ct universe and ΛCDM - and show that Rh = ct is favoured by the CDD data with a likelihood ~82.3 per cent compared with ~17.7 per cent for the standard model.
AB - The cosmic distance duality (CDD) relation (based on the Etherington reciprocity theorem) plays a crucial role in awide assortment of cosmological measurements. Attempts at confirming it observationally have met with mixed results, though the general consensus appears to be that the data do support its existence in nature. A common limitation with past approaches has been their reliance on a specific cosmological model, or on measurements of the luminosity distance to Type Ia SNe, which introduces a dependence on the presumed cosmology in spite of beliefs to the contrary. Confirming that the CDD is actually realized in nature is crucial because its violation would require exotic new physics. In this paper, we study the CDD using the observed angular size of compact quasar cores and aGaussian Process reconstruction of the HII galaxy Hubble diagram - without pre-assuming any particular background cosmology. In so doing, we confirm at a very high level of confidence that the angular-diameter and luminosity distances do indeed satisfy the CDD. We then demonstrate the potential power of this result by utilizing it in a comparative test of two competing cosmological models - the Rh = ct universe and ΛCDM - and show that Rh = ct is favoured by the CDD data with a likelihood ~82.3 per cent compared with ~17.7 per cent for the standard model.
KW - Cosmological parameters
KW - Cosmology: observations
KW - Cosmology: theory
KW - Distance scale
KW - Galaxies: active
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U2 - 10.1093/MNRAS/STY2596
DO - 10.1093/MNRAS/STY2596
M3 - Article
AN - SCOPUS:85060916891
VL - 481
SP - 4855
EP - 4862
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -