Validity Of Cosmic Distance Duality Relation Research Articles

Testing the cosmic distance duality relation with Type Ia supernova and transverse BAO measurements

In this work, we test the cosmic distance duality relation (CDDR) by comparing the angular diameter distance (ADD) derived from the transverse Baryon Acoustic Oscillations (BAO) data with the luminosity distance (LD) from the Pantheon type Ia supernova (SNIa) sample. The binning method and Gaussian process are employed to match ADD data with LD data at the same redshift. First, we use nonparametric and parametric methods to investigate the impact of the specific prior values of the absolute magnitude MB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M_\ extrm{B}$$\\end{document} from SNIa observations and the sound horizon scale rs\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$r_\ extrm{s}$$\\end{document} from transverse BAO measurements on the CDDR tests. The results obtained from the parametric and non-parametric methods indicate that specific prior values of MB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M_\ extrm{B}$$\\end{document} and rs\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$r_\ extrm{s}$$\\end{document} lead to significant biases on the CDDR test. Then, to avoid these biases, we propose a method independent of MB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M_\ extrm{B}$$\\end{document} and rs\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$r_\ extrm{s}$$\\end{document} to test CDDR by considering the fiducial value of κ≡10MB5rs\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\kappa \\equiv 10^{M_\ extrm{B} \\over 5}r_\ extrm{s}$$\\end{document} as a nuisance parameter and then marginalizing its influence with a flat prior in the analysis. No violation of the CDDR is found, and the transverse BAO measurement can be used as a powerful tool to verify the validity of CDDR in the cosmological-model-independent method.

Low redshift calibration of the Amati relation using galaxy clusters

In this work, we use the angular diameter distances of 38 galaxy clusters with joint X-ray/SZE observation to circumvent the circularity problem in the Amati relation for Gamma-ray Bursts (GRBs). Assuming the validity of cosmic-distance duality relation, we obtain the luminosity distance from the cluster angular diameter distance and use that to calculate the isotropic equivalent energy of two different GRB datasets, after restricting the GRB redshift range to z < 0.9. We then use these GRB datasets to test the Amati relation at the low redshifts using the galaxy cluster distances. Our best-fit Amati relation parameters are consistent with a previous estimate for the same dataset. The intrinsic scatter which we obtain for the two datasets is about 45% and 15%, and is comparable with that found by other distance anchors used to study the Amati relation.

A non-parametric test of variability of Type Ia supernovae luminosity and CDDR

The first observational evidence for cosmic acceleration appeared from Type Ia supernovae (SNe Type Ia) Hubble diagram from two different groups. However, the empirical treatment of SNe Type Ia and their ability to show cosmic acceleration have been the subject of some debate in the literature. In this work we probe the assumption of redshift-independent absolute magnitude (MB) of SNe along with its correlation with spatial curvature (Ωk0) and cosmic distance duality relation (CDDR) parameter (η(z)). This work is divided into two parts. Firstly, we check the validity of CDDR which relates the luminosity distance (dL) and angular diameter distance (dA) via redshift. We use the Pantheon SNe Ia dataset combined with the H(z) measurements derived from the cosmic chronometers. Further, four different redshift-dependent parametrizations of the distance duality parameter (η(z)) are used. The CDDR is fairly consistent for almost every parametrization within a 2σ confidence level in both flat and a non-flat universe. In the second part, we assume the validity of CDDR and emphasize on the variability of M_B and its correlation with Ωk0. We choose four different redshift-dependent parametrizations of MB. The results indicate no evolution of MB within 2σ confidence level. For all parametrizations, the best fit value of Ωk0 indicates a flat universe at 2σ confidence level. However a mild inclination towards a non flat universe is also observed. We have also examined the dependence of the results on the choice of different priors for H0.

Revisiting the cosmic distance duality relation with machine learning reconstruction methods: the combination of HII galaxies and ultra-compact radio quasars

In this paper, we carry out an assessment of cosmic distance duality relation (CDDR) based on the latest observations of HII galaxies acting as standard candles and ultra-compact structure in radio quasars acting as standard rulers. Particularly, two machine learning reconstruction methods [Gaussian Process (GP) and Artificial Neural Network (ANN)] are applied to reconstruct the Hubble diagrams from observational data. We show that both approaches are capable of reconstructing the current constraints on possible deviations from the CDDR in the redshift range zsim 2.3. Considering four different parametric methods of CDDR, which quantify deviations from the CDDR and the standard cosmological model, we compare the results of the two different machine learning approaches. It is observed that the validity of CDDR is in well agreement with the current observational data within 1sigma based on the reconstructed distances through GP in the overlapping redshift domain. Moreover, we find that ultra-compact radio quasars could provide 10^{-3}-level constraints on the violation parameter at high redshifts, when combined with the observations of HII galaxies. In the framework of ANN, one could derive robust constraints on the violation parameter at a precision of 10^{-2}, with the validity of such distance duality relation within 2sigma confidence level.

New tests of the cosmic distance duality relation with the baryon acoustic oscillation and type Ia supernovae

The cosmic distance duality relation (CDDR), $$\eta (z)\equiv (1+z)^{-2}D_{\mathrm{{L}}}/D_{\mathrm{{A}}}=1$$ , plays a fundamental role in cosmology and astronomy since any violation of CDDR could be a signal of new physics. In this paper, we re-test the validity of CDDR by using the newest baryon acoustic oscillations (BAO) measurements from baryon oscillation spectroscopic survey data release 12 and the latest Pantheon type Ia supernovae (SNIa) sample. Using three parameterizations of $$\eta (z)$$ , namely $$\eta (z)=1+\eta _1 z$$ , $$\eta (z)=1+\eta _2 \frac{z}{1+z}$$ and $$\eta (z)=1+\eta _3\mathrm{ln}(1+z)$$ , and considering the effects of the uncertainty of dimensionless Hubble constant h, we find that the CDDR is valid at $$1\sigma $$ confidence level (CL) whether h is free or marginalized over with a flat prior distribution. However, when marginalizing over h with two different Gaussian distributions, we find that the CDDR is valid at $$2\sigma $$ CL with $$h=0.6727\pm 0.0060$$ , while it is valid only at $$4\sigma $$ CL with $$h=0.7403\pm 0.0142$$ . Our results show that although using the newest BAO measurements and Pantheon SNIa sample can significantly improve the accuracy of $$\eta (z)$$ , more precise data points of angular diameter distance and luminosity distance as well as accurate measurement of h are needed to test the validity of CDDR.

Multiple Measurements of Quasars Acting as Standard Probes: Exploring the Cosmic Distance Duality Relation at Higher Redshift

Abstract General relativity reproduces main current cosmological observations, assuming the validity of the cosmic distance duality relation (CDDR) at all scales and epochs. However, CDDR is poorly tested in the redshift interval between the farthest observed Type Ia supernovae and that of the cosmic microwave background. We present a new idea of testing the validity of CDDR, through the multiple measurements of high-redshift quasars. Luminosity distances are derived from the relation between the UV and X-ray luminosities of quasars, while angular diameter distances are obtained from the compact structure in radio quasars. This will create a valuable opportunity where two different cosmological distances from the same kind of objects at high redshifts are compared. Our constraints are more stringent than other currently available results based on different observational data and show no evidence for the deviation from CDDR at z ∼ 3. Such an accurate model-independent test of fundamental cosmological principles can become a milestone in precision cosmology.

Forecasting constraints on the cosmic duality relation with galaxy clusters

One of the fundamental hypotheses in observational cosmology is the validity of the so-called cosmic distance-duality relation. In this paper, we perform Monte Carlo simulations based on the method developed in Holanda, Gon\ifmmode \mbox{\c{c}}\else \c{c}\fi{}alves, and Alcaniz [J. Cosmol. Astropart. Phys. 06 (2012) 022] to answer the following question: what is the number of galaxy clusters observations ${N}_{\text{crit}}$ needed to check the validity of this relation at a given confidence level? At $2\ensuremath{\sigma}$, we find that ${N}_{\text{crit}}$ should be increased at least by a factor of 5 relative to the current sample size if we assume the current observational uncertainty ${\ensuremath{\sigma}}_{\text{obs}}$. Reducing this latter quantity by a factor of 2, we show that the present amount of data would be already close to the required number to check the validity of the cosmic distance-duality relation at $2\ensuremath{\sigma}$.

Observational cosmology and the cosmic distance duality relation

We study the validity of cosmic distance dualityrelation between angular diameter and luminosity distances. Totest this duality relation we use the latest Union2 Supernovae TypeIa (SNe Ia) data for estimating the luminosity distance. The estimationof angular diameter distance comes from the samples of galaxyclusters (real and mock) and FRIIb radio galaxies. We parameterize the distanceduality relation as a function of redshift in six different ways.Our results rule out some of the parameterizations significantly.