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Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 Md Ishaque Khan , Rajib Saha

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

In this article we propose a novel test for statistical anisotropy of the CMB. The test is based on the fact, that the Galactic foregrounds have a remarcably strong symmetry with respect to their antipodal points and with respect to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 P. Naselsky , M. Hansen , J. Kim

We provide perturbation theory predictions for the HI intensity mapping power spectrum multipoles using the Effective Field Theory of Large Scale Structure (EFTofLSS), which should allow us to constrain cosmological parameters exploiting…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-02 Alkistis Pourtsidou

We develop the formalism necessary to study four-point functions of the cosmic microwave background (CMB) temperature and polarization fields. We determine the general form of CMB trispectra, with the constraints imposed by the assumption…

Astrophysics · Physics 2011-05-12 Takemi Okamoto , Wayne Hu

Isocurvature perturbations expected from multi-field inflation models can leave unique signatures in the early Universe, but remain weakly constrained, especially on small scales. In this work, we investigate the constraining power of…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-19 Zhenfei Qin , Hayato Shimabukuro

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

The statistical expectation values of the temperature fluctuations of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. This assumption of {\em statistical isotropy} (SI) of the CMB anisotropy should…

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

A recent study of the rotation of the plane of polarization of light from 160 cosmological sources claims to find significant evidence for cosmological anisotropy. We point out methodological weaknesses of that study, and reanalyze the same…

Astrophysics · Physics 2009-12-30 Thomas J. Loredo , Eanna E. Flanagan , Ira M. Wasserman

Measurements of CMB anisotropy and, more recently, polarization have played a very important role in cosmology. Besides precise determination of various parameters of the `standard' cosmological model, observations have also established…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Tarun Souradeep

We use weighted mean and median statistics techniques to combine individual cosmic microwave background (CMB) anisotropy detections and determine binned, multipole-space, CMB anisotropy power spectra. The resultant power spectra are peaked.…

Cosmic microwave background (CMB) temperature anisotropies have and will continue to revolutionize our understanding of cosmology. The recent discovery of the previously predicted acoustic peaks in the power spectrum has established a…

Astrophysics · Physics 2011-07-19 Wayne Hu , Scott Dodelson

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark…

Astrophysics · Physics 2016-01-13 J. Richard Bond , George Efstathiou , Max Tegmark

We present a formalism for analyzing interferometric observations of Cosmic Microwave Background (CMB) anisotropy and polarization data. The formalism is based upon the ell-space expansion of the angular power spectrum favoured in recent…

Astrophysics · Physics 2009-08-18 Martin White , John E. Carlstrom , Mark Dragovan , William L. Holzapfel

Much of modern cosmology relies on the Cosmological Principle, the assumption that the Universe is isotropic and homogeneous on sufficiently large scales, but it remains worthwhile to examine cosmological models that violate this principle…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-01 Ananda F. Smith , Craig J. Copi , Glenn D. Starkman

We suggest that the solution to the cosmological vacuum energy puzzle does not require any new field beyond the standard model, but rather can be explained as a result of the interaction of the infrared sector of the effective theory of…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-13 Federico R. Urban , Ariel R. Zhitnitsky

The Cosmic Microwave Background anisotropies are difficult to measure at large angular scales. In this paper, we present a new analysis of the \Planck\ High Frequency Instrument data that brings the cosmological part and its major…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-09 J. -M. Delouis , J. -L. Puget , L. Vibert

The advent of high signal-to-noise cosmic microwave background (CMB) anisotropy experiments has allowed detailed studies on the power spectrum of temperature fluctuations. The existence of acoustic oscillations in the anisotropy power…

Astrophysics · Physics 2009-11-07 Asantha Cooray

Measurements of the cosmic 21 cm signal need to achieve a high dynamic range to isolate it from bright foreground emissions. Calibration inaccuracies can compromise the spectral fidelity of the smooth foreground continuum, thereby limiting…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Pascal M. Keller , Bojan Nikolic , Nithyanandan Thyagarajan

We report the most complete analysis to date of observations of the Cosmic Microwave Background (CMB) obtained during the 1998 flight of BOOMERANG. We use two quite different methods to determine the angular power spectrum of the CMB in 20…