English
Related papers

Related papers: Large scale vector modes and the first CMB tempera…

200 papers

The observed dipole asymmetry in Cosmic Microwave Background radiation may have originated from the modulations of super-horizon long wavelength modes. In this work we unveil different aspects of asymmetries generated from the long…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Ali Akbar Abolhasani , Shant Baghram , Hassan Firouzjahi , Mohammad Hossein Namjoo

WMAP and Planck may have uncovered several anomalies in the full CMB sky that could indicate possible new physics driving the growth of density fluctuations in the early Universe. These include an unusually low power at the largest scales…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-26 Fulvio Melia

Recent observations have identified a significant 4.9$\sigma$ tension between the cosmic dipole inferred from galaxy number counts and that derived from the Cosmic Microwave Background (CMB), suggesting a potential deviation from the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-29 Ge Chen , Chengcheng Han , Linwei Qiu

The connection between the dipolar modulation asymmetry and the quadrupole-octopole alignment in the CMB is studied in this work. First, a generalization of the dipolar modulation model is proposed by considering that the amplitude may…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 A. Marcos-Caballero , E. Martínez-González

We revisit the alignments of the largest structures observed in the cosmic microwave background (CMB) using the seven and nine-year WMAP and first-year Planck data releases. The observed alignments -- the quadrupole with the octopole and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

We propose a novel representation of cosmic microwave anisotropy maps, where each multipole order l is represented by l unit vectors pointing in directions on the sky and an overall magnitude. These "multipole vectors and scalars" transform…

Astrophysics · Physics 2008-11-26 C. J. Copi , D. Huterer , G. D. Starkman

We study the cosmic microwave background (CMB) temperature fluctuations non-gaussianity due to the vector mode perturbations (Alfv\'en waves) supported by a stochastic cosmological magnetic field. We present detailed derivations of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-01 Tina Kahniashvili , George Lavrelashvili

Recent work has emphasised the importance of vector and tensor contributions to the large scale microwave anisotropy fluctuations produced by cosmic defects. In this paper we provide a general discussion of these contributions, and how…

Astrophysics · Physics 2008-11-26 Neil Turok , Ue-Li Pen , Uros Seljak

We reconsider analysis of data on the cosmic microwave background on the largest angular scales. Temperature multipoles of any order factor naturally into a direct product of axial quantities and cosets. Striking coincidences exist among…

Astrophysics · Physics 2011-09-13 John P. Ralston , Pankaj Jain

The Cosmic Microwave Background (CMB) reaches homogeneity at relatively modest angular scales compared to the expectation of the standard $\Lambda$CDM model revealing an important challenge to the theoretical predictions. We analyze this…

In both WMAP and Planck observations on the temperature anisotropy of cosmic microwave background (CMB) radiation a number of large-scale anomalies were discovered in the past years, including the CMB parity asymmetry in the low multipoles.…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-22 Wen Zhao , Larissa Santos

The large-angular-scale falloff in the autocorrelation function for the cosmic microwave background (CMB) temperature has long intrigued cosmologists and fueled speculation about suppressed superhorizon power. Here we highlight an…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-13 Jahmour J. Givans , Marc Kamionkowski

We investigate a possible asymmetry in the statistical properties of the cosmic microwave background temperature field and to do so we construct an estimator aiming at detecting a dipolar modulation. Such a modulation is found to induce…

Astrophysics · Physics 2009-11-10 Simon Prunet , Jean-Philippe Uzan , Francis Bernardeau , Tristan Brunier

The temperature perturbations of the cosmic microwave background radiation (CMB) appear systematically suppressed, at large angular scales, with respect to the prediction of the LambdaCDM concordance model. This behavior might be a glimpse…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Noriaki Kitazawa

We introduce new, low-$\ell$, multipole vectors for the CMB temperature fluctuations. A very strong alignment of the quadrupole and octopole vectors is observed as well as a remarkably low declination of these vectors with respect to the…

Astrophysics · Physics 2007-05-23 M. Glück , C. Pisano

In this work we investigate the standard deviation of the Cosmic Microwave Background (CMB) temperature gradient field as a signature for a multiply connected nature of the Universe. CMB simulations of a spatially infinite universe model…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-02 Ralf Aurich , Thomas Buchert , Martin J. France , Frank Steiner

In recent years, large radio surveys of Active Galactic Nuclei (AGNs), comprising millions of sources, have become available where one could investigate dipole asymmetries, assumedly arising due to a peculiar motion of the Solar system.…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-21 Ashok K. Singal

Measurements of the cosmic microwave background (CMB) temperature anisotropies have revealed a dipolar asymmetry in power at the largest scales, in apparent contradiction with the statistical isotropy of standard cosmological models. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 D. Contreras , J. Hutchinson , A. Moss , D. Scott , J. P. Zibin

We explore the large angular scale temperature anisotropies in the cosmic microwave background due to expanding homogeneous local voids at redshift z~1. A compensated spherically symmetric homogeneous dust-filled void with radius \~3*10^2…

Astrophysics · Physics 2008-11-26 Kaiki Taro Inoue , Joseph Silk

We extend the curvaton scenario presented by Erickcek et al. (2008, 2009), to explain how the even-odd multipole asymmetry of the Cosmic Microwave Background (CMB) (also called parity asymmetry, (Kim & Naselsky 2010)) and power anisotropies…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-29 Hao Liu , Anne Mette Frejsel , Pavel Naselsky