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Related papers: A new method for testing isotropy with Shannon ent…

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(Abridged) We study the properties of anisotropic and axisymmetric velocity ellipsoids from maps of the gas velocity dispersion in nearby galaxies. This data allow us to measure the azimuthal-to-radial axis ratio of gas velocity ellipsoids,…

Astrophysics of Galaxies · Physics 2020-08-05 Laurent Chemin , Jonathan Braine , Françoise Combes , Zacharie S. Kam , Claude Carignan

The cosmological principle assumes that the universe is homogeneous and isotropic on cosmic scales. There exist many works testing the cosmic homogeneity and/or the cosmic isotropy of the universe in the literature. In fact, some…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Hua-Kai Deng , Hao Wei

The statistical tests - done by the authors - are surveyed, which verify the null-hypothesis of the intrinsic randomness in the angular distribution of gamma-ray bursts collected at BATSE Catalog. The tests use the counts-in-cells method,…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Meszaros , Z. Bagoly , L. G. Balazs , I. Horvath , R. Vavrek

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

A spatial point pattern is called anisotropic if its spatial structure depends on direction. Several methods for anisotropy analysis have been introduced in the literature. In this paper, we give an overview of nonparametric methods for…

Methodology · Statistics 2018-03-01 Tuomas Rajala , Claudia Redenbach , Aila Särkkä , Martina Sormani

Motivated by the central role played by rotationally symmetric distributions in directional statistics, we consider the problem of testing rotational symmetry on the hypersphere. We adopt a semiparametric approach and tackle problems where…

Methodology · Statistics 2021-04-27 Eduardo García-Portugués , Davy Paindaveine , Thomas Verdebout

This paper addresses the problem of detecting and estimating the anisotropy of a stationary real-valued random field from a single realization of one of its excursion sets. This setting is challenging as it relies on observing a binary…

Methodology · Statistics 2025-12-15 Jean-Marc Azaïs , Federico Dalmao , Yohann De Castro

AIMS. To check whether the polar angle distribution of QSOs around nearby spiral galaxies is isotropic or not. METHODS. A statistical analysis of the polar angle distribution of large samples of QSOs from the SDSS survey and Monte Carlo…

Astrophysics · Physics 2009-11-11 M. Lopez-Corredoira , C. M. Gutierrez

A new method for analyzing point patterns produced by the evolution of gravitational clustering is presented. The method is taken from the study of molecular liquids, where it has been introduced for making a statistical description of…

Astrophysics · Physics 2009-10-31 R. Valdarnini

It is not obvious how to extend Shannon's original information entropy to higher dimensions, and many different approaches have been tried. We replace the English text symbol sequence originally used to illustrate the theory by a discrete,…

Information Theory · Computer Science 2016-09-06 Kieran G. Larkin

In parallel with advances in microscale imaging techniques, the fields of biology and materials science have focused on precisely extracting particle properties based on their diffusion behavior. Although the majority of real-world…

Mesoscale and Nanoscale Physics · Physics 2024-05-22 Kaito Takanami , Daisuke Taniguchi , Sawako Enoki , Masafumi Kuroda , Yasushi Okada , Yoshiyuki Kabashima

We test claims of large-scale anisotropy in the local expansion rate using cluster scaling relations as distance indicators. Using a Bayesian forward model, we jointly fit the X-ray luminosity--temperature (LT) and thermal…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Tariq Yasin , Richard Stiskalek , Harry Desmond , Sebastian von Hausegger , Pedro G. Ferreira

The Shannon entropy is a fundamental measure for quantifying diversity and model complexity in fields such as information theory, ecology, and genetics. However, many existing studies assume that the number of species is known, an…

Methodology · Statistics 2026-02-23 Takato Hashino , Koji Tsukuda

We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Godel's metric and is classified as Bianchi III. This metric is an exact…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-23 W. Miranda , S. Carneiro , C. Pigozzo

We investigate distributional properties of a class of spectral spatial statistics under irregular sampling of a random field that is defined on $\mathbb{R}^d$, and use this to obtain a test for isotropy. Within this context, edge effects…

Statistics Theory · Mathematics 2024-01-17 Theresa Eckle , Anne van Delft , Holger Dette

Recently, a Monte Carlo method has been presented which allows for the form-free retrieval of size distributions from isotropic scattering patterns, complete with uncertainty estimates linked to the data quality. Here, we present an…

Data Analysis, Statistics and Probability · Physics 2013-03-13 Brian R. Pauw , Masato Ohnuma , Kenji Sakurai , Enno A. Klop

The cosmological principle, as the cornerstone of the standard cosmological model, requires that the Universe be homogeneous and isotropic on large scales. As a fundamental assumption, it is constantly subjected to testing via various…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-21 Jianping Hu , Chao Geng , Xuandong Jia , Zhaoyu Zuo , Taozhi Yang , Fayin Wang

Recent observational analyses have suggested possible evidence of hemisphere asymmetry in cosmological datasets. Parameterizations of this kind place observers in a privileged position-specifically on the plane that divides the two…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Xin Wang , Zhiqi Huang

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 evaluate reflected entropy in certain anisotropic boundary theories dual to nonrelativistic geometries using holography. It is proposed that this quantity is proportional to the minimal area of the entanglement wedge cross section. Using…

High Energy Physics - Theory · Physics 2025-01-23 Mohammad Javad Vasli , M. Reza Mohammadi Mozaffar , Komeil Babaei Velni , Mohammad Sahraei