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We investigate the hemispherical power asymmetry in the cosmic microwave background on small angular scales. We find an anomalously high asymmetry in the multipole range l=601-2048, with a naive statistical significance of 6.5 sigma.…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-30 Samuel Flender , Shaun Hotchkiss

Cosmic microwave background anisotropies encode crucial information about the early Universe and fundamental cosmological physics. Although the standard $\Lambda$CDM model provides a successful description of cosmic evolution, persistent…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Yang Han , Lu Chen , Guo-Hao Li , Pei-Yuan Xu

The measurement of the large scale distribution of neutral hydrogen in the late Universe, obtained with radio telescopes through the hydrogen 21cm line emission, has the potential to become a key cosmological probe in the upcoming years. We…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Maria Berti , Marta Spinelli , Matteo Viel

It is discovered in our previous work that different observational systematics, e.g., errors of antenna pointing directions, asynchronous between the attitude and science data, can generate pseudo-dipole signal in full-sky maps of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-19 Hao Liu , Ti-Pei Li

Motivated by WMAP's confirmation of an anomalously low value of the quadrupole moment of the CMB temperature fluctuations, we investigate the effects on the CMB of cutting off the primordial power spectrum P(k) at low wave numbers. This…

Astrophysics · Physics 2009-11-07 James M. Cline , Patrick Crotty , Julien Lesgourgues

The presence of a dipolar statistical anisotropy in the spectrum of cosmic microwave background (CMB) fluctuations was reported by the Wilkinson Microwave Anisotropy Probe (WMAP), and has recently been confirmed in the Planck 2013 analysis…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-29 Sugumi Kanno , Misao Sasaki , Takahiro Tanaka

We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) using data from the South Pole Telescope (SPT). The data consist of 790 square degrees of sky observed at 150 GHz during 2008 and 2009. Here we…

The Atacama Cosmology Telescope has measured the angular power spectra of microwave fluctuations to arcminute scales at frequencies of 148 and 218 GHz, from three seasons of data. At small scales the fluctuations in the primordial Cosmic…

Several accurate analyses have revealed a statistically significant North-South ecliptic asymmetry in the large-angle correlations strength of the Cosmic Microwave Background (CMB) radiation temperature field data from the Wilkinson…

Astrophysics · Physics 2009-02-23 Armando Bernui

At the largest angular scales the presence of a number of unexpected features has been confirmed by the latest measurements of the cosmic microwave background (CMB). Among them are the anomalous alignment of the quadrupole and octopole with…

Astrophysics · Physics 2008-11-26 Aleksandar Rakic , Dominik J. Schwarz

We analyze the alignment of the low multipoles (quadrupole and octupole) of various maps of the WMAP 5yr release: the CMB maps obtained with ILC and MCMC methods, the CMB map in the V band after foreground reduction, and, for comparison,…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Alessandro Gruppuso , Carlo Burigana

We use a Quadratic Maximum Likelihood (QML) method to estimate the angular power spectrum of the cross-correlation between cosmic microwave background and large scale structure maps as well as their individual auto-spectra. We describe our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 F. Schiavon , F. Finelli , A. Gruppuso , A. Marcos-Caballero , P. Vielva , R. G. Crittenden , R. B. Barreiro , E. Martinez-Gonzalez

We discuss how an extended foreground of the cosmic microwave background (CMB) can account for the anomalies in the low multipoles of the CMB anisotropies. The distortion needed to account for the anomalies is consistent with a cold spot…

Astrophysics · Physics 2009-11-11 L. Raul Abramo , Laerte Sodre , Carlos Alexandre Wuensche

We carry out the determination of the amplitude of relic gravitational waves power spectrum. Indirect best-fit technique was applied to compare observational data and theory predictions. As observations we have used data on large-scale…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , S. Apunevych

In cosmic microwave background (CMB) experiments, foreground-cleaned temperature maps are still contaminated by the residual dipole due to uncertainties of the Doppler dipole direction and microwave radiometer sidelobe. To obtain reliable…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-16 Hao Liu , Ti-Pei Li

We propose a fast and efficient bispectrum statistic for Cosmic Microwave Background (CMB) temperature anisotropies to constrain the amplitude of the primordial non-Gaussian signal measured in terms of the non-linear coupling parameter…

Astrophysics · Physics 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Cheng Cheng , Qing-Guo Huang

We show that the thermal Sunyaev-Zeldovich effect caused by hot electrons in the Local Supercluster (LSC) can explain the abnormal quadrupole and octopole of the cosmic microwave background (CMB) that were measured by WMAP and COBE. The…

Astrophysics · Physics 2007-05-23 L. Raul Abramo , L. Sodre

The Cosmic Radio Dipole is of fundamental interest to cosmology. Recent studies revealed open questions about the nature of the observed Cosmic Radio Dipole. We use simulated source count maps to test a linear and a quadratic estimator for…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-07 Thilo M. Siewert , Matthias Schmidt-Rubart , Dominik J. Schwarz

The large-angle (low-l) correlations of the Cosmic Microwave Background exhibit several statistically significant anomalies compared to the standard inflationary big-bang model, however no connection has hitherto been drawn between them.…

Astrophysics · Physics 2009-11-10 Dominik J. Schwarz , Glenn D. Starkman , Dragan Huterer , Craig J. Copi