One of the fundamental hypotheses in observational cosmology is the validity of the so-called cosmic distance-duality relation (CDDR). In this paper, we perform Monte Carlo simulations based on the method developed in Holanda, Goncalves & Alcaniz (2012) [JCAP 1206 (2012) 022] to answer the following question: what is the number of galaxy clusters observations N_{crit} needed to check the validity of this relation at a given confidence level? At 2σ, we find that N_{crit} should be increased at least by a factor of 5 relative to the current sample size if we assume the current observational uncertainty σ_{obs}. Reducing this latter quantity by a factor of 2, we show that the present number of data would be already enough to check the validity of the CDDR at 2σ.
We compare distance measurements obtained from two distance indicators, Super- novae observations (standard candles) and Baryon acoustic oscillation data (standard rulers). The Union2 sample of supernovae with BAO data from SDSS, 6dFGS and the latest BOSS and WiggleZ surveys is used in search for deviations from the distance duality relation. We find that the supernovae are brighter than expected from BAO measurements. The luminosity distances tend to be smaller then expected from angular diameter distance estimates as also found in earlier works on distance duality, but the trend is not stati…
We use simulated strongly lensed gravitational wave events from the Einstein Telescope to demonstrate how the luminosity and angular diameter distances, $d_L(z)$ and $d_A(z)$ respectively, can be combined to test in a model independent manner for deviations from the cosmic distance duality relation and the standard cosmological model. In particular, we use two machine learning approaches, the Genetic Algorithms and Gaussian Processes, to reconstruct the mock data and we show that both approaches are capable of correctly recovering the underlying fiducial model and can provide percent-level con…
We study the validity of cosmic distance duality relation between angular diameter and luminosity distances. To test this duality relation we use the latest Union2 Supernovae Type Ia (SNe Ia) data for estimating the luminosity distance. The estimation of angular diameter distance comes from the samples of galaxy clusters (real and mock) and FRIIb radio galaxies. We parameterize the distance duality relation as a function of redshift in six different ways. Our results rule out some of the parameterizations significantly.
A violation of the reciprocity relation, which induces a violation of the distance duality relation, reflects itself in a change in the normalisation of the cosmic microwave spectrum in such a way that its spectrum is grey. We show that existing observational constraints imply that the reciprocity relation cannot be violated by more than 0.01% between decoupling and today. We compare this effect to other sources of violation of the distance duality relations which induce spectral distortion of the cosmic microwave background spectrum.
We obtain the current constraint on the minimally extended varying speed of light (meVSL) model by analyzing cosmic distance duality relation (CCDDR) of it, $D_{L}/D_{A}(1+z)^{-2} = (1+z)^{b/8}$. We use the Pantheon type Ia supernova (SNIa) data, the Hubble parameter $H(z)$ using the cosmic chronometers approach, and the cosmic microwave background (CMB) distance priors from the latest Planck data. We find that the current data show the 1-$σ$ deviation from the standard CCDDR. Thus, this provides the constraint on meVSL model and future precision observations might be able to put stronger cons…
We carry out a test of the cosmic distance duality relation using a sample of 52 SPT-SZ clusters, along with X-ray measurements from XMM-Newton. To carry out this test, we need an estimate of the luminosity distance ($D_L$) at the redshift of the cluster. For this purpose, we use three independent methods: directly using $D_L$ from the closest Type Ia Supernovae from the Union 2.1 sample, non-parametric reconstruction of $D_L$ using the same Union 2.1 sample, and finally using $H(z)$ measurements from cosmic chronometers and reconstructing $D_L$ using Gaussian Process regression. We use four d…
We propose a new method to test the cosmic distance duality relation using the strongly lensed gravitational waves. The simultaneous observations of image positions, the relative time delay between different images, the redshift measurements of lens and source, together with the mass modelling of the lens galaxy, provide the angular diameter distance to the gravitational wave source. On the other hand, from the observation of gravitational wave signals the luminosity distance to the source can be obtained. This is to our knowledge the first method to simultaneously measure both the angular dia…
Testing the cosmic distance duality relation (CDDR) constitutes an important task for cosmology and fundamental physics since any violation of it would be a clear evidence of new physics. In this {\it Letter}, we propose a new test for the CDDR using only measurements of the gas mass fraction of galaxy clusters from Sunyaev-Zeldovich ($f_{SZE}$) and X-ray surface brightness ($f_{X-ray}$) observations. We show that the relation between current $f_{X-ray}$ and $f_{SZE}$ observations is given by $f_{SZE}=ηf_{X-ray}$, where $η$ quantifies deviations from the CDDR. Since this latter expression is v…
In this paper we discuss a new cosmological model-independent test for the cosmic distance duality relation (CDDR), $η= D_{L}(L)(1+z)^{-2}/D_{A}(z)=1$, where $D_{A}(z)$ and $D_{L}(z)$ are the angular and luminosity distances, respectively. Using the general expression for X-ray gas mass fraction ($f_{gas}$) of galaxy clusters, $f_{gas} \propto D_L{D_A}^{1/2}$, we show that $f_{gas}$ observations jointly with type Ia supernovae (SNe Ia) data furnish a validity test for the CDDR. To perform our analysis we use 38 $f_{gas}$ measurements recently studied by two groups considering different assumpt…
Under certain general conditions in an expanding universe, the luminosity distance (d_L) and angular diameter distance (d_A) are connected by the Etherington relation as d_L = d_A (1 + z)^2. The Tolman test suggests the use of objects of known surface brightness, to test this relation. In this letter, we propose the use of redshifted 21 cm signal from disk galaxies, where neutral hydrogen (HI) masses are seen to be almost linearly correlated with surface area, to conduct a new Tolman test. We construct simulated catalogs of galaxies, with the observed size-luminosity relation and realistic red…
The distance-duality relation (DDR) between the luminosity distance $D_L$ and the angular diameter distance $D_A$ is viewed as a powerful tool for testing for the opacity of the Universe, being independent of any cosmological model. It was applied by many authors, who mostly confirm its validity and report a negligible opacity of the Universe. Nevertheless, a thorough analysis reveals that applying the DDR in cosmic opacity tests is tricky. Its applicability is strongly limited because of a non-unique interpretation of the $D_L$ data in terms of cosmic opacity and a rather low accuracy and def…
In this paper, we carry out a new model-independent cosmological test for the cosmic distance duality relation~(CDDR) by combining the latest five baryon acoustic oscillations (BAO) measurements and the Pantheon type Ia supernova (SNIa) sample. Particularly, the BAO measurement from extended Baryon Oscillation Spectroscopic Survey~(eBOSS) data release~(DR) 16 quasar sample at effective redshift $z=1.48$ is used, and two methods, i.e. a compressed form of Pantheon sample and the Artificial Neural Network~(ANN) combined with the binning SNIa method, are applied to overcome the redshift-matching …
The cosmic distance duality relation (DDR) is constrained from the combination of type-Ia supernovae (SNe Ia) and strong gravitational lensing (SGL) systems using deep learning method. To make use of the full SGL data, we reconstruct the luminosity distance from SNe Ia up to the highest redshift of SGL using deep learning, then it is compared with the angular diameter distance obtained from SGL. Considering the influence of lens mass profile, we constrain the possible violation of DDR in three lens mass models. Results show that in the SIS model and EPL model, DDR is violated at high confidenc…
The cosmic distance relation (DDR) associates the angular diameters distance ($D_A$) and luminosity distance ($D_L$) by a simple formula, i.e., $D_L=(1+z)^2D_A$. The strongly lensed gravitational waves (GWs) provide a unique way to measure $D_A$ and $D_L$ simultaneously to the GW source, hence can be used as probes to test DDR. In this paper, we prospect the use of strongly lensed GW events from the future Einstein Telescope to test DDR. We write the possible deviation of DDR as $(1+z)^2D_A/D_L=η(z)$, and consider two different parametrizations of $η(z)$, namely, $η_1(z)=1+η_0 z$ and $η_2(z)=1…
The cosmic distance duality relation (CDDR) has been test through several astronomical observations in the last years. This relation establishes a simple equation relating the angular diameter ($D_A$) and luminosity ($D_L$) distances at a redshift $z$, $D_LD_A^{-1}(1+z)^{-2}=η=1$. However, only very recently this relation has been observationally tested at high redshifts ($z \approx 3.6$) by using luminosity distances from type Ia supernovae (SNe Ia) and gamma ray bursts (GRBs) plus angular diameter distances from strong gravitational lensing (SGL) observations. The results show that no signif…
Constraints on the Hubble parameter, $H_0$, via X-ray surface brightness and Sunyaev-Zel'dovich effect (SZE) observations of the galaxy clusters depend on the validity of the cosmic distance duality relation (DD relation), $η= D_{L}(z)(1+z)^{-2}/D_{A}(z) = 1$, where $D_L$ and $D_A$ are the luminosity distance and angular diameter distance (ADD), respectively. In this work, we argue that if the DD relation does not hold the X-ray plus SZE technique furnishes a $H^{*}_{0}=H_{0}/η^{2}$. We use 25 ADD of galaxy clusters to obtain simultaneous constraints on $H_{0}$ and possible violation of the DD…
The cosmic distance duality (CDD) relation (based on the Etherington reciprocity theorem) plays a crucial role in a wide 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 …
{In this paper, we use large scale structure observations to test the redshift dependence of cosmic distance duality relation (CDDR), $D_{\rm L}(1+z)^{-2}/D_{\rm A}=η(z)$}, with $D_{\rm L}$ and $D_{\rm A}$, being the luminosity and angular diameter distances, respectively. In order to perform the test, the following data set are considered: strong lensing systems and galaxy cluster measurements (gas mass fractions). No specific cosmological model is adopted, only a flat universe is assumed. { By considering two $η(z)$ parametrizations, It is observed that the CDDR remain redshift independent w…
The cosmic distance duality relation (CDDR), $D_{\rm L}(1+z)^{-2}/D_{\rm A}=η=1$, with $D_{\rm L}$ and $D_{\rm A}$, being the luminosity and angular diameter distances, respectively, is a crucial premise in cosmological scenarios. Many investigations try to test CDDR through observational approaches, even some of these ones also consider a deformed CDDR, i.e., $η=η(z)$. In this paper, we use type Ia supernovae luminosity distances and galaxy cluster measurements (their angular diameter distances and gas mass fractions) in order to perform a Bayesian model comparison between $ η(z) $ functions.…
A validation of the cosmic distance duality (CDD) relation, eta(z)=(1+z)^2 d_A(z)/d_L(z)=1, coupling the luminosity (d_L) and angular-diameter (d_A) distances, is crucial because its violation would require exotic new physics. We present a model-independent test of the CDD, based on strong lensing and a reconstruction of the HII galaxy Hubble diagram using Gaussian Processes, to confirm the validity of the CDD at a very high level of confidence. Using parameterizations eta(z) = 1 + eta_0 z and eta(z) = 1 + eta_1 z + eta_2 z^2, our best-fit results are eta_0 = 0.0147^{+0.056}_{-0.066}, and eta_…
In this paper, we use the model dependent method to revisit the constraint on the well-known cosmic distance duality relation (CDDR). By using the latest SNIa samples, such as Union2.1, JLA and SNLS, we find that the SNIa data alone can not constrain the cosmic opacity parameter $\varepsilon$, which denotes the deviation from the CDDR, $d_{\rm L} = d_{\rm A}(1+z)^{2+\varepsilon}$, very well. The constraining power on $\varepsilon$ from the luminosity distance indicator provided by SNIa and GRB is hardly to be improved at present. When we include other cosmological observations, such as the mea…
We compare two different probes of the expansion history of the universe, namely, luminosity distances from type Ia supernovae and angular diameter distances from galaxy clusters, using the Bayesian interpretation of Crossing statistic [1, 2] in conjunction with the assumption of cosmic duality relation. Our analysis is conducted independently of any a-priori assumptions about the nature of dark energy. The model independent method which we invoke searches for inconsistencies between SNIa and galaxy cluster data sets. If detected such an inconsistency would imply the presence of systematics in…
General relativity reproduces main current cosmological observations, assuming the validity of 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 (SN Ia) and that of the Cosmic Microwave background (CMB). 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 comp…
The cosmic distance duality relation (CDDR) is a fundamental assumption in cosmological studies. Given the redshift $z$, it relates luminosity distance $D^L$ with angular diameter distance $D^A$ through $(1+z)^2D^A/D^L\equiv1$. Many efforts have been devoted to test the CDDR with various observational approaches. However, to the best of our knowledge, those methods are always affected by cosmic opacity which could make the CDDR violated due to the non-conservation of photon number. Such mechanism is more related with astropartical physics. In this work, to directly study the nature of space-ti…
We forecast the ability of cosmic microwave background (CMB) temperature and polarization datasets to constrain theories of eternal inflation using cosmic bubble collisions. Using the Fisher matrix formalism, we determine both the overall detectability of bubble collisions and the constraints achievable on the fundamental parameters describing the underlying theory. The CMB signatures considered are based on state-of-the-art numerical relativistic simulations of the bubble collision spacetime, evolved using the full temperature and polarization transfer functions. Comparing a theoretical cosmi…
The basic cosmological distances are linked by the Etherington cosmic distance duality relation, $η(z) = D_{L}(z)(1+z)^{-2}/D_{A}(z) \equiv 1$, where $D_{L}$ and $D_{A}$ are, respectively, the luminosity and angular diameter distances. In order to test its validity, some authors have proposed phenomenological expressions for $η(z)$ thereby deforming the original Etherington's relation and comparing the resulting expressions with the available and future cosmological data. The relevance of such studies is unquestionable since any violation of the cosmic distance duality relation could be the si…
We propose and perform a new test of the cosmic distance-duality relation (CDDR), $D_L(z) / D_A(z) (1 + z)^{2} = 1$, where $D_A$ is the angular diameter distance and $D_L$ is the luminosity distance to a given source at redshift $z$, using strong gravitational lensing (SGL) and type Ia Supernovae (SNe Ia) data. We show that the ratio $D=D_{A_{12}}/D_{A_2}$ and $D^{*}=D_{L_{12}}/D_{L_{2}}$, where the subscripts 1 and 2 correspond, respectively, to redshifts $z_1$ and $z_2$, are linked by $D/D^*=(1+z_1)^2$ if the CDDR is valid. We allow departures from the CDDR by defining two funcions for $η(z_…
A distance-deviation consistency and model-independent method to test the cosmic distance duality relation (CDDR) is provided. The method is worth attention on two aspects: firstly, a distance-deviation consistency method is used to pair subsamples: instead of pairing subsamples with redshift deviation smaller than a \textbf{value}, say $\left\vert Δz\right\vert <0.005$. The redshift deviation between subsamples decreases with the redshift to ensure the distance deviation stays the same. The method selects more subsamples at high redshift, up to $z=2.16$, and provides 120 subsample pairs. Seco…
In this paper, we propose a new test to the cosmic distance duality relation (CDDR), $D_L=D_A(1+z)^2$, where $D_L$ and $D_A$ are the luminosity and angular diameter distances, respectively. The data used correspond to 61 Type Ia Supernova luminosity distances and $Y_{SZE}-Y_X$ measurements of 61 galaxy clusters obtained by the {\it Planck} mission and the deep XMM-Newton X-ray data, where $Y_{SZE}$ is the integrated comptonization parameter obtained via Sunyaev-Zel'dovich effect observations and $Y_X$ is the X-ray counterpart. More precisely, we use the $Y_{SZE}D_{A}^{2}/C_{XSZE}Y_X$ scaling-r…
We propose a consistency test of some recent X-ray gas mass fraction ($f_{\rm{gas}}$) measurements in galaxy clusters, using the cosmic distance-duality relation, $η_{\rm{theory}}=\dl(1+z)^{-2}/\da$, with luminosity distance ($\dl$) data from the Union2 compilation of type Ia supernovae. We set $η_{\rm{theory}}\equiv1$, instead of assigning any redshift parameterizations to it, and constrain the cosmological information preferred by $f_{\rm{gas}}$ data along with supernova observations. We adopt a new binning method in the reduction of the Union2 data, in order to minimize the statistical erro…
Next-generation wide-field spectroscopic surveys will observe the infall regions around large numbers of galaxy clusters with high sampling rates for the first time. Here we assess the feasibility of extracting the large-scale cosmic web around clusters using forthcoming observations, given realistic observational constraints. We use a sample of 324 hydrodynamic zoom-in simulations of massive galaxy clusters from TheThreeHundred project to create a mock-observational catalogue spanning $5R_{200}$ around 160 analogue clusters. These analogues are matched in mass to the 16 clusters targetted by …
The construction of the cosmic distance-duality relation (CDDR) has been widely studied. However, its consistency with various new observables remains a topic of interest. We present a new way to constrain the CDDR $η(z)$ using different dynamic and geometric properties of strong gravitational lenses (SGL) along with SNe Ia observations. We use a sample of $102$ SGL with the measurement of corresponding velocity dispersion $σ_0$ and Einstein radius $θ_E$. In addition, we also use a dataset of $12$ two image lensing systems containing the measure of time delay $Δt$ between source images. Jointl…
Observations in the cosmological domain are heavily dependent on the validity of the cosmic distance-duality (DD) relation, D_L(z) (1 + z)^{2}/D_{A}(z) = 1, an exact result required by the Etherington reciprocity theorem where D_L(z) and D_A(z) are, respectively, the luminosity and angular diameter distances. In the limit of very small redshifts D_A(z) = D_L(z) and this ratio is trivially satisfied. Measurements of Sunyaev-Zeldovich effect (SZE) and X-rays combined with the DD relation have been used to determine D_A(z)from galaxy clusters. This combination offers the possibility of testing th…
Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile ($ρ\propto r^{-γ}$) is consistent with the cosmic distance duality relation (CDDR), $D_L(1+z)^{-2}/D_A=η(z)=1$, by considering different lens mass intervals. { It …
In this paper, we investigate the possible deviations of the cosmic distance duality relation (CDDR) using the combination of the largest SNe Ia (Pantheon) and compact radio quasar (QSO) samples through two model-independent approaches. The deviation of CDDR is written as $D_L(z)/D_A(z)(1+z)^{-2}=η(z)$ and $η(z)=e^{τ(z)/2}$, with the parameterizations of $F_1$ ($τ(z) = 2ε_1 z$) and $F_2$ ($τ(z) = (1+z)^{2ε_2}-1$). Furthermore, in order to compare the two resulting distances, two cosmological-model-independent methods, i.e., the nearby SNe Ia method and the GP method are employed to match the t…
Revisiting the cosmic distance duality relation with machine learning reconstruction methods: the combination of HII galaxies and ultra-compact radio quasars
The angular diameter distances toward galaxy clusters can be determined with measurements of the Sunyaev-Zel'dovich effect and X-ray surface brightness combined with the validity of the distance-duality relation, $D_L(z) (1 + z)^{2}/D_{A}(z) = 1$, where $D_L(z)$ and $D_A(z)$ are, respectively, the luminosity and angular diameter distances. This combination enables us to probe galaxy cluster physics or even to test the validity of the distance-duality relation itself. We explore these possibilities based on two different, but complementary approaches. Firstly, in order to constrain the possible…
We present results from end-to-end simulations of observations designed to constrain the rate of change in the expansion history of the Universe using the redshift drift of the Lyman-$α$ forest absorption lines along the lines-of-sight toward bright quasars. For our simulations we take Lyman-$α$ forest lines extracted from Keck/HIRES spectra of bright quasars at $z>3$, and compare the results from these real quasar spectra with mock spectra generated via Monte Carlo realizations. We use the results of these simulations to assess the potential for a dedicated observatory to detect redshift drif…
