Model-independent constraints on the cosmic opacity

Abstract

We use current measurements of the expansion rate H(z) and cosmic background radiation bounds on the spatial curvature of the Universe to impose cosmological model-independent constraints on cosmic opacity. To perform our analyses, we compare opacity-free distance modulus from H(z) data with those from two type Ia supernovae compilations, namely, the Union2.1 plus the most distant spectroscopically confirmed SNe Ia (SCP-0401 at z = 1.713) and two Sloan Digital Sky Survey (SDSS) subsamples. We find that a completely transparent universe is in full agreement with the Union 2.1 + SNe Ia SCP-0401 sample. For the SDSS compilations, such universe is compatible with observations at < 1.5σ level regardless the SNe Ia light-curve fitting used.

Is the Universe transparent?

“…Based on previous works [28,29], we introduce an improved method to get luminosity distances that are not affected by cosmic opacity and are also independent of any specific cosmological model. We consider constructing 19 luminosity distances D H L (z n ), n = 1, 2...19, from the H(z) data at the corresponding redshifts by:…”

“…On the other hand, in Refs. [24,[28][29][30], distances derived from other opacity-independent probes, e.g. observational determinations of the Hubble parameter H(z) based on differential ageing of passively evolving galaxies (also dubbed "cosmic chronometers") [31], were proposed to test or even quantify cosmic opacity by comparing these distances with those from SN Ia observations.…”

“…What is more, in Refs. [28,29], the authors constructed luminosity distances from H(z) data but did not take the correlations between different redshifts into account. This treatment would lead to inaccurate estimations of the errors.…”

Two new tests to the distance duality relation with galaxy clusters

“…We follow the methodology firstly presented by [30] where one transforms H(z) measurements into cosmological distance estimates by solving numerically the comoving distance integral for non-uniformly spaced data, i.e.,…”

Constraining axionlike particles using the distance-duality relation

“…Holanda et al [85] parametrized the redshift dependence of η(z) in two distinct forms, η(z) = 1 + η 0 z(P1) and η(z) = 1 + η 0 z/(1 + z)(P2) and investigated the η 0 parameter by employing the luminosity distance D L measurements from Type Ia supernovae (SNe Ia) and diameter distance D A from galaxy clusters [86,87]. Several other authors have also tested the DDR relation using different observations: SNe Ia plus cosmic microwave background (CMB) and barion acoustic oscillations (BAO) [88], SNe Ia plus H(z) data [77,[89][90][91], gas mass fraction of galaxy clusters and SNe Ia [92,93], CMB spectrum [94], gammaray burst (GRB) plus H(z) [95], SNe Ia plus BAO [96], gas mass fraction plus H(z) [97], gravitational lensing plus SNe Ia [98], SNe Ia and radio galaxy plus CMB [99]. Most of the above authors obtain no significant deviation in DDR relation, although, roughly the scatter in η 0 parameter is observed as ±0.1 to ±0.…”