English
Related papers

Related papers: Probing large scale homogeneity and periodicity in…

200 papers

We analyze a set of volume limited samples from SDSS DR12 to quantify the degree of inhomogeneity at different length scales using Shannon entropy. We find that the galaxy distributions exhibit a higher degree of inhomogeneity as compared…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-21 Biswajit Pandey , Suman Sarkar

We analyze a set of volume limited sample of galaxies from the SDSS to study the issue of cosmic homogeneity. We use the Renyi entropy of different order to probe the inhomogeneties present in the galaxy distributions. We also calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Biswajit Pandey , Suman Sarkar

We test the homogeneity of the Universe at $z\sim 0.3$ with the Luminous Red Galaxy (LRG) spectroscopic sample of the Sloan Digital Sky Survey. First, the mean number $N(R)$ of LRGs within completely surveyed LRG-centered spheres of…

The assumption that the Universe, on sufficiently large scales, is homogeneous and isotropic is crucial to our current understanding of cosmology. In this paper we test if the observed galaxy distribution is actually homogeneous on large…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Prakash Sarkar , Jaswant Yadav , Biswajit Pandey , Somnath Bharadwaj

We report measurements of the angular scale of cosmic homogeneity ($\theta_{H}$) using the recently released luminous red galaxy sample of the sixteenth data release of the Sloan Digital Sky Survey (SDSS-IV LRG DR16). It consists of a…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-28 Uendert Andrade , Rodrigo S. Gonçalves , Gabriela C. Carvalho , Carlos A. P. Bengaly , Joel C. Carvalho , Jailson Alcaniz

The assumption that the universe is homogeneous and isotropic on large scales is one of the fundamental postulates of cosmology. We have tested the large scale homogeneity of the galaxy distribution in the Sloan Digital Sky Survey Data…

Astrophysics · Physics 2009-11-11 J. Yadav , S. Bharadwaj , B. Pandey , T. R. Seshadri

Filaments are one of the most prominent features visible in the galaxy distribution. Considering the Luminous Red Galaxies (LRGs) in the Sloan Digital Sky Survey Data Release Seven (SDSS DR7), we have analyzed the filamentarity in 11 nearly…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Biswajit Pandey , Gauri Kulkarni , Somnath Bharadwaj , Tarun Souradeep

Observationally confirming spatial homogeneity on sufficiently large cosmological scales is of importance to test one of the underpinning assumptions of cosmology, and is also imperative for correctly interpreting dark energy. A challenging…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Ben Hoyle , Rita Tojeiro , Raul Jimenez , Alan Heavens , Chris Clarkson , Roy Maartens

We present measurements of the genus topology of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Data Release 7 catalog, with unprecedented statistical significance. To estimate the uncertainties in the measured genus,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Yun-Young Choi , Juhan Kim , Graziano Rossi , Sungsoo S. Kim , Jeong-Eun Lee

We propose a method for testing cosmic homogeneity based on the Shannon entropy in Information theory and test the potentials and limitations of the method on Monte Carlo simulations of some homogeneous and inhomogeneous 3D point process in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Biswajit Pandey

A statistical analysis of radial distributions of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS DR7) catalogue within an interval $0.16 \leq z \leq 0.47$ is carried out. We found that the radial distribution of $\sim$…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-25 Andrei I. Ryabinkov , Alexander A. Kaurov , Alexander D. Kaminker

We carry out multifractal analyses of multiple tracers namely the main galaxy sample, the LRG sample and the quasar sample from the SDSS to test the assumption of cosmic homogeneity and identify the scale of transition to homogeneity, if…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-24 Prakash Sarkar , Subhabrata Majumdar , Biswajit Pandey , Atul Kedia , Suman Sarkar

We measure the 3D genus topology of large scale structure using Luminous Red Galaxies (LRGs) in the Sloan Digital Sky Survey and find it consistent with the Gaussian random phase initial conditions expected from the simplest scenarios of…

Astrophysics · Physics 2019-08-13 J. Richard Gott , Yun-Young Choi , Changbom Park , Juhan Kim

We apply the scale-length method to several three dimensional samples of the Two degree Field Galaxy Redshift Survey. This method allows us to map in a quantitative and powerful way large scale structures in the distribution of galaxies…

Astrophysics · Physics 2009-08-03 Francesco Sylos Labini , Nikolay L. Vasilyev , Yurij V. Baryshev

We consider the effect on the propagation of light of inhomogeneities with sizes of order 10 Mpc or larger. The Universe is approximated through a variation of the Swiss-cheese model. The spherical inhomogeneities are void-like, with…

Astrophysics · Physics 2010-02-17 Nikolaos Brouzakis , Nikolaos Tetradis , Eleftheria Tzavara

We propose a novel method for testing isotropy of a three-dimensional distribution using Shannon entropy. We test the method on some Monte Carlo simulations of isotropic and anisotropic distributions and find that the method can effectively…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Biswajit Pandey

Using the 2MASS Photometric Redshift catalogue we perform a number of statistical tests aimed at detecting possible departures from statistical homogeneity and isotropy in the large-scale structure of the Universe. Making use of the angular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 David Alonso , Ana Isabel Salvador , Francisco Javier Sánchez , Maciej Bilicki , Juan García-Bellido , Eusebio Sánchez

We propose a method for testing homogeneity in three dimensional spatial distributions using Renyi entropy. We apply the proposed method to data from cosmological N-body simulations and Monte Carlo simulations of homogeneous Poisson point…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-16 Biswajit Pandey

The statistical measure of spatial inhomogeneity for n points placed in chi cells each of size kxk is generalized to incorporate finite size objects like black pixels for binary patterns of size LxL. As a function of length scale k, the…

Statistical Mechanics · Physics 2009-11-11 Ryszard Piasecki

We analyze the SDSS DR12 quasar catalogue to test the large-scale smoothness in the quasar distribution. We quantify the degree of inhomogeneity in the quasar distribution using information theory based measures and find that the degree of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Suman Sarkar , Biswajit Pandey
‹ Prev 1 2 3 10 Next ›