Probing cosmic opacity at high redshifts with gamma-ray bursts

Abstract

Probing the evolution of the universe at high redshifts with standard candles is a powerful way to discriminate dark energy models, where an open question nowadays is whether this component is constant or evolves with time. One possible source of ambiguity in this kind of analyses comes from cosmic opacity, which can mimick a dark enery behaviour. However, most tests of cosmic opacity have been restricted to the redshift range z < 2. In this work, by using luminosity distances of gamma-ray bursts (GRBs), given the validity of the Amati relation, and the latest H(z) data we determine constraints on the cosmic opacity at high redshifts (z > 2) for a flat ΛCDM model. A possible degenerescence of the results with the adopted cosmological model is also investigated by considering a flat XCDM model. The limits on cosmic opacity in the redshift range 0 < z < 2 are updated with type Ia supernovae (SNe Ia) from the Union2.1 sample, where we added the most distant (z = 1.713) spectroscopically confirmed SNe Ia. From the analyses performed, we find that both SNe Ia and GRBs samples are compatible with a transparent universe at 1σ level and the results are independent of the dark energy equation of state parameter w.

Is the Universe transparent?

“…Recently, a great deal of effort has been devoted in checking the validity of the DDR with astronomical observations [14][15][16][17][18][19]. Meanwhile, there were also many studies that focused on testing cosmic opacity under the assumption that any possible deviations from the DDR originate from nonconservation of the number of photons between emission at the source and detection [6,20,[27][28][29][30]. There are two general ways to carry out these studies.…”

“…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.…”

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.…”

Cosmic transparency and acceleration

“…[25,26] used current measurements of the expansion rate H(z) and SNe Ia data in a flat ΛCDM model and showed that a transparent universe is in agreement with the data considered (ε ≈ 0). H(z) data and luminosity distances of gamma ray bursts (GRBs) and SNe Ia in ΛCDM and ωCDM flat models were considered to explore the possible existence of an opacity at higher redshifts (z > 2) [33]. Again, the results indicated the transparency of the universe, but with large error bars.…”