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Unexpected features have been observed in the cosmic microwave background (CMB) temperature on large scales. We revisit these CMB anomalies using new foreground-cleaned CMB temperature maps derived in a companion paper from WMAP and Planck…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-05 Laura Herold , Graeme E. Addison , Charles L. Bennett , Hayley C. Nofi , J. L. Weiland

We combine detections of anisotropy in the Cosmic Microwave Background radiation with observations of inhomogeneity in the large-scale distribution of galaxies to test the predictions of models of cosmological structure formation. This…

Astrophysics · Physics 2009-09-25 Eric Gawiser

To minimize instrumentally induced systematic errors, cosmic microwave background (CMB) anisotropy experiments measure temperature differences across the sky using paires of horn antennas, temperature map is recovered from temperature…

Astrophysics · Physics 2009-08-30 Hao Liu , Ti-Pei Li

We study the angular distribution of temperature fluctuations in the cosmic microwave background (CMB) to probe the statistical isotropy of the universe by using precise full-sky CMB data with a model-independent approach. We investigated…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-01 C. E. Kester , A. Bernui , W. S. Hipólito-Ricaldi

The scalar mode temperature fluctuations of the cosmic microwave background has been derived in a spatially closed universe from two different methods. First, by following the photon trajectory after the last scattering and then from the…

General Relativity and Quantum Cosmology · Physics 2017-09-27 Pedram Niazy , Amir H. Abbassi

We compute the fully non-linear Cosmic Microwave Background (CMB) anisotropies on scales larger than the horizon at last-scattering in terms of only the curvature perturbation, providing a generalization of the linear Sachs-Wolfe effect at…

Astrophysics · Physics 2009-11-13 N. Bartolo , S. Matarrese , A. Riotto

We analyse the anisotropy of the cosmic microwave background (CMB) in hyperbolic universes possessing a non-trivial topology with a fundamental cell having an infinitely long horn. The aim of this paper is twofold. On the one hand, we show…

Astrophysics · Physics 2009-11-10 Ralf Aurich , Sven Lustig , Frank Steiner , Holger Then

We study the cosmic microwave background (CMB) anisotropy in the scenario where the baryon asymmetry of the universe is generated from a condensation of a scalar field. In such a scenario, the scalar condensation may acquire fluctuation…

High Energy Physics - Phenomenology · Physics 2009-09-29 Takeo Moroi , Hitoshi Murayama

We briefly review certain aspects of cosmic microwave background anisotropies as generated in passive and active models of structure formation. We then focus on cosmic strings based models and discuss their status in the light of current…

Astrophysics · Physics 2009-11-07 Alejandro Gangui , Levon Pogosian , Serge Winitzki

The Cosmic Microwave Background (CMB) anisotropy constrains the geometry of the Universe because the positions of the acoustic peaks of the angular power spectrum depend strongly on the curvature of underlying three-dimensional space. In…

Astrophysics · Physics 2009-11-13 J. Dunkley , M. Bucher , P. G. Ferreira , K. Moodley , C. Skordis

The past, present and future of cosmic microwave background (CMB) anisotropy research is discussed, with emphasis on the Boomerang and Maxima balloon experiments. These data are combined with large scale structure (LSS) information and high…

The standard cosmological model predicts statistically isotropic cosmic microwave background (CMB) fluctuations characterized by the CMB temperature coefficients $a_{\ell m}$ being independent Gaussian random variables with zero mean and…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-17 Joann Jones , Craig J. Copi , Glenn D. Starkman , Yashar Akrami

Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data confirm the ellipticity of anisotropies of Cosmic Microwave Background (CMB) maps, found previously for Boomerang and WMAP 1-year high sensitivity maps. The low noise level of the WMAP…

Astrophysics · Physics 2008-11-26 V. G. Gurzadyan , C. L. Bianco , A. L. Kashin , H. Kuloghlian , G. Yegorian

We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear $\delta…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Hooshyar Assadullahi , Hassan Firouzjahi , Mohammad Hossein Namjoo , David Wands

The weak lensing effect on the cosmic microwave background (CMB) induces distortions in spatial pattern of CMB anisotropies, and statistical properties of CMB anisotropies become a weakly non-Gaussian field. We first summarize the weak…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-17 Toshiya Namikawa

Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-05 Duncan Hanson , Antony Lewis , Anthony Challinor

We present a new, model-independent approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern. Our approach is based on the empirical distribution function of the normalized spherical harmonic…

Astrophysics · Physics 2011-05-10 Frode K. Hansen , Domenico Marinucci , Paolo Natoli , Nicola Vittorio

Skewness of temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational…

Astrophysics · Physics 2009-10-28 Dipak Munshi , Tarun Souradeep , Alexei A. Starobinsky

We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-02 Tim Clunan , David Seery

We consider a perfectly homogeneous, isotropic and spatially flat universe which undergoes a sudden phase transition producing topological defects. We assume that these defects form a coherent network which scales like the background…

Astrophysics · Physics 2007-05-23 Jean-Philippe Uzan , Nathalie Deruelle , Alain Riazuelo