English
Related papers

Related papers: Sampling Effects on Cosmological Dipoles

200 papers

The flux ratios of strongly lensed quasars have previously been used to infer the properties of dark matter. In these analyses it is crucial to separate the effect of the main lensing galaxy and the low-mass dark matter halo population. In…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-19 Jacob S. Cohen , Christopher D. Fassnacht , Conor M. O'Riordan , Simona Vegetti

It was recently shown that the power spectrum in redshift space can be written as a sum of cross-power spectra between number weighted velocity moments. We investigate the properties of these power spectra for simulated galaxies and dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Teppei Okumura , Uros Seljak , Vincent Desjacques

We study biasing as a physical phenomenon by analysing power spectra (PS) and correlation functions (CF) of simulated galaxy samples and dark matter (DM) samples. We apply an algorithm based on the local densities of particles, $\rho$, to…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-03 Jaan Einasto

We critically investigate current statistical tests applied to high redshift clusters of galaxies in order to test the standard cosmological model and describe their range of validity. We carefully compare a sample of high-redshift,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Ben Hoyle , Raul Jimenez , Licia Verde , Shaun Hotchkiss

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

We present a new approach to constructing and fitting dipoles and higher-order multipoles in synthetic galaxy samples over the sky. Within our Bayesian paradigm, we illustrate that this technique is robust to masked skies, allowing us to…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-18 Oliver T. Oayda , Vasudev Mittal , Geraint F. Lewis

We use the PSCz IRAS galaxy redshift survey to analyze the cosmological galaxy dipole out to a distance 300 h$^{-1}$ Mpc. The masked area is filled in three different ways, firstly by sampling the whole sky at random, secondly by using…

The abundance of clusters of galaxies is highly sensitive to the late-time evolution of the matter distribution, since clusters form at the highest density peaks. However, the 3D cluster mass cannot be inferred without deprojecting the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-29 Stijn N. B. Debackere , Henk Hoekstra , Joop Schaye , Katrin Heitmann , Salman Habib

We critically assess the impact of significant dipole and large-scale anisotropies on galaxy clustering signals, with a focus on radio continuum surveys. Our study reveals that these anisotropies -- resulting from intrinsic cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-15 Prabhakar Tiwari

Our peculiar motion in a homogeneous and isotropic universe imprints a dipole in the cosmic microwave background (CMB) temperature field and similarly imprints a dipole in the distribution of extragalactic radio sources on the sky. Each of…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Calum Murray

The cosmic dipole tension - the discrepancy between the Cosmic Microwave Background kinematic dipole and the matter dipole inferred from all-sky surveys poses a significant challenge to the Cosmological Principle, which dictates that the…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-28 Vasudev Mittal , Geraint F. Lewis

Context. The large-scale mass distribution around dark matter haloes hosting galaxy clusters provides sensitive cosmological information. Aims. In this work, we make use of a large photometric galaxy cluster sample, constructed from the…

We examine the errors on counts in cells extracted from galaxy surveys. The measurement error, related to the finite number of sampling cells, is disentangled from the ``cosmic error'', due to the finiteness of the survey. Using the…

Astrophysics · Physics 2009-10-28 István Szapudi , Stéphane Colombi

We investigate clustering properties of dark matter halos and galaxies to search for optimal statistics and scales where possible departures from general relativity (GR) could be found. We use large N-body cosmological simulations to…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Jorge Enrique García-Farieta , Wojciech A. Hellwing , Suhani Gupta , Maciej Bilicki

We study dynamical mass measurements of galaxy clusters contaminated by interlopers and show that a modern machine learning (ML) algorithm can predict masses by better than a factor of two compared to a standard scaling relation approach.…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 M. Ntampaka , H. Trac , D. J. Sutherland , S. Fromenteau , B. Poczos , J. Schneider

We present a simulation-based inference framework using a convolutional neural network to infer dynamical masses of galaxy clusters from their observed 3D projected phase-space distribution, which consists of the projected galaxy positions…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-18 Doogesh Kodi Ramanah , Radosław Wojtak , Nikki Arendse

We present a maximum-likelihood analysis of galaxy-galaxy lensing effects in galaxy clusters and in the field. The aim is to determine the accuracy and robustness of constraints that can be obtained on galaxy halo properties in both…

Astrophysics · Physics 2009-11-10 Marceau Limousin , Jean Paul Kneib , Priyamvada Natarajan

A key test of the isotropy of the Universe on large scales consists in comparing the dipole in the Cosmic Microwave Background (CMB) temperature with the dipole in the distribution of sources at low redshift. Current analyses find a dipole…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 N. Grimm , M. Pijnenburg , S. Mastrogiovanni , C. Bonvin , S. Foffa , G. Cusin

We examine how the statistics of the quadrupoles of (projected) cluster masses can discriminate between flat cold dark matter (CDM) universes with or without a cosmological constant term. Even in the era of high precision cosmology that…

Astrophysics · Physics 2009-11-06 A. Maccio` , A. Gardini , S. Ghigna , S. A. Bonometto

We present a method to obtain a high-significance detection of relativistic effects on cosmological scales. Measurements of such effects would be instrumental for our understanding of the Universe, as they would provide a further…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-19 Federico Montano , Stefano Camera