English
Related papers

Related papers: Testing the statistical isotropy of large scale st…

200 papers

We propose a new internal linear combination (ILC) method in the pixel space, applicable on large angular scales of the sky, to estimate a foreground minimized Cosmic Microwave Background (CMB) temperature anisotropy map by incorporating…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Vipin Sudevan , Rajib Saha

We probe the statistical isotropy hypothesis of the large-scale structure with the second Planck Sunyaev-Zeldovich (PSZ2) galaxy clusters data set. Our analysis adopts a statistical-geometrical method which compares the 2-point angular…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-15 C. A. P. Bengaly , A. Bernui , I. S. Ferreira , J. S. Alcaniz

Large scale structure deflects cosmic microwave background (CMB) photons. Since large angular scales in the large scale structure contribute significantly to the gravitational lensing effect, a realistic simulation of CMB lensing requires a…

Astrophysics · Physics 2009-11-13 Sudeep Das , Paul Bode

The ten's of micro-Kelvin variations in the temperature of the cosmic microwave background (CMB) radiation across the sky encode a wealth of information about the Universe. The full-sky, high-resolution maps of the CMB that will be made in…

Astrophysics · Physics 2007-05-23 Martin White

We examine all-sky cosmic microwave background (CMB) temperature maps on large angular scales to compare their consistency with two scenarios: the standard inflationary quantum picture, and a distribution constrained to have a universal…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-13 Nathaniel Selub , Frederick Wehlen , Craig Hogan , Stephan S. Meyer

We present a comparative analysis of estimators and Bayesian methods for determining the number count dipole from cosmological surveys. The increase in discordance between the number count dipole and the CMB's kinematic dipole has presented…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-30 Vasudev Mittal , Oliver T. Oayda , Geraint F. Lewis

Low multipoles ($l$) in cosmic microwave background (CMB) temperature anisotropies have shown some `peculiarities' when examined since the release of the full sky CMB maps, using a variety of tests. In this paper, we concern ourselves with…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Pavan Kumar Aluri , Sanjeet Kumar Patel

The statistical expectation values of the temperature fluctuations of the Cosmic Microwave Background (CMB) are assumed to be preserved under rotations of the sky. We investigate the Statistical Isotropy (SI) of the CMB anisotropy maps…

Astrophysics · Physics 2009-11-10 Amir Hajian , Tarun Souradeep , Neil Cornish

The data from Cosmic Microwave Background (CMB) experiments are becoming more complex with each new experiment. A consistent way of analysing these data sets is required so that direct comparison is possible between the various experimental…

Astrophysics · Physics 2007-05-23 A. W. Jones

A conventional explanation of the dipole anisotropy of the cosmic microwave background (CMB) radiation is in terms of the Doppler effect: our galaxy is moving with respect to CMB frame with $ \sim 600 ~ km ~ s^{-1} $. However, as the deep…

Astrophysics · Physics 2007-05-23 M. Jaroszynski , B. Paczynski

We study the ellipticity of contour lines in the sky maps of the cosmic microwave background (CMB) as well as other measures of elongation. The sensitivity of the elongation on the resolution of the CMB maps which depends on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Ralf Aurich , Holger S. Janzer , Sven Lustig , Frank Steiner

We propose to use a simple observable, the fractional area of "hot spots" in weak lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-shear regions are directly…

Astrophysics · Physics 2008-09-24 Sheng Wang , Zoltan Haiman , Morgan May , John Kehayias

The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Cyrille Doux , Mariana Penna-Lima , Sandro D. P. Vitenti , Julien Tréguer , Eric Aubourg , Ken Ganga

We perform detailed calculations of cosmic microwave background (CMB) anisotropies in a CDM-dominated open universe with primordial adiabatic density perturbations for a variety of reionization histories. We show that to a great extent, the…

Astrophysics · Physics 2009-10-22 Marc Kamionkowski , David N. Spergel , Naoshi Sugiyama

The cosmic microwave background (CMB) anisotropies are a powerful probe of the early universe, and have largely contributed to establishing the current standard cosmological model. To extract the information encoded in those tiny…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-17 Simon Biquard

We investigate the large scale anomalies in the angular distribution of the cosmic microwave background radiation as measured by WMAP using several tests. These tests, based on the multipole vector expansion, measure correlations between…

We use a recent Pantheon+SH0ES compilation of Type Ia Supernova distance measurements at low-redshift, i.e., $0.01 \leq z \leq 0.10$, in order to investigate the directional dependency of the deceleration parameter ($q_0$) in different…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-27 Carlos A. P. Bengaly , Cássio Pigozzo , Jailson S. Alcaniz

Deviations from statistical isotropy can be modeled in various ways, for instance, anisotropic cosmological models (Bianchi models), compact topologies and presence of primordial magnetic field. Signature of anisotropy manifests itself in…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Nidhi Joshi , Sanjay Jhingan , Tarun Souradeep , Amir Hajian

We consider the issue of characterizing the coherent large-scale patterns from CMB temperature maps in globally anisotropic cosmologies. The methods we investigate are reasonably general; the particular models we test them on are the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Rockhee Sung , Jo Short , Peter Coles

Search for the statistical anisotropy in the CMB data is a powerful tool for constraining models of the early Universe. In this paper we focus on the recently proposed cosmological scenario with conformal rolling. We consider two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 S. R. Ramazanov , G. I. Rubtsov