Measuring the transition to homogeneity with photometric redshift surveys

Abstract

We study the possibility of detecting the transition to homogeneity using photometric redshift catalogs. Our method is based on measuring the fractality of the projected galaxy distribution, using angular distances, and relies only on observable quantites. It thus provides a way to test the Cosmological Principle in a model-independent unbiased way. We have tested our method on different synthetic inhomogeneous catalogs, and shown that it is capable of discriminating some fractal models with relatively large fractal dimensions, in spite of the loss of information due to the radial projection. We have also studied the influence of the redshift bin width, photometric redshift errors, bias, non-linear clustering, and surveyed area, on the angular homogeneity index H2 (θ) in a ΛCDM cosmology. The level to which an upcoming galaxy survey will be able to constrain the transition to homogeneity will depend mainly on the total surveyed area and the compactness of the surveyed region. In particular, a Dark Energy Survey (DES)-like survey should be able to easily discriminate certain fractal models with fractal dimensions as large as D2 = 2.95. We believe that this method will have relevant applications for upcoming large photometric redshift surveys, such as DES or the Large Synoptic Survey Telescope (LSST).

14 pages, 14 figures

References in corpus (4)

• Confronting Lemaitre-Tolman-Bondi models with Observational Cosmology
• Tracing The Sound Horizon Scale With Photometric Redshift Surveys
• Fractal Dimensions of a Weakly Clustered Distribution and the Scale of Homogeneity
• The effect of redshift-space distortions on projected 2-pt clustering measurements

Cited by in corpus (14)

• Cosmology and Fundamental Physics with the Euclid Satellite
• Homogeneity and isotropy in the 2MASS Photometric Redshift catalogue
• The intrinsic bispectrum of the Cosmic Microwave Background [PhD thesis]
• Testing Isotropy in the Local Universe
• Cosmic homogeneity: a spectroscopic and model-independent measurement
• The scale of homogeneity in the local Universe with the ALFALFA catalogue
• The angular scale of homogeneity in the Local Universe with the SDSS blue galaxies
• Constraints on Cosmology and Baryonic Feedback with the Deep Lens Survey Using Galaxy-Galaxy and Galaxy-Mass Power Spectra
• A measurement of the scale of homogeneity in the Early Universe
• Scale-dependent homogeneity measures for causal dynamical triangulations
• Mapping the Cosmic Web with the largest all-sky surveys
• Can the homogeneity scale be used as a standard ruler?
• Can the angular scale of cosmic homogeneity be used as a cosmological test?
• Revisiting the CMB homogeneity scale: low multipoles removal effect and extragalactic foreground masking