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Related papers: CMB ANISOTROPIES: AN OVERVIEW

200 papers

We explore the hemispherical asymmetry predicted in cosmic microwave background polarization when there is an asymmetry in temperature anisotropies due to primordial perturbations. We consider the cases of asymmetries due to adiabatic and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. H. Namjoo , A. A. Abolhasani , H. Assadullahi , S. Baghram , H. Firouzjahi , D. Wands

The origin of power asymmetry and other measures of statistical anisotropy on the largest scales of the universe, as manifested in Cosmic Microwave Background (CMB) and large-scale structure data, is a long-standing open question in…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-12 Pablo Fosalba , Enrique Gaztanaga

We provide a new derivation of the anisotropies of the cosmic microwave background (CMB), and find an exact expression that can be readily expanded perturbatively. Close attention is paid to gauge issues, with the motivation to examine the…

Astrophysics · Physics 2009-01-08 J. P. Zibin , Douglas Scott

The cosmic microwave background (CMB), the relic radiation from the early Universe, offers a unique window into both primordial conditions and the intervening large-scale structure (LSS) it traverses. Interactions between CMB photons and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-24 Federico Bianchini , Abhishek S. Maniyar

The quality of CMB observations has improved dramatically in the last few years, and will continue to do so in the coming decade. Over a wide range of angular scales, the uncertainty due to instrumental noise is now small compared to the…

The status of the standard cosmological model, also known as "LCDM" is described. With some simple assumptions, this model fits a wide range of data, with just six (or seven) free parameters. One should be skeptical about this claim, since…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-05 Douglas Scott

Non-linear evolution of cosmological energy density fluctuations triggers deviations from Gaussianity in the temperature distribution of the cosmic microwave background. A method to estimate these deviations is proposed. N-body simulations…

Astrophysics · Physics 2009-11-07 A. M. Aliaga , V. Quilis , J. V. Arnau , D. Saez

We investigate the point-parity and mirror-parity handedness of the large angle anisotropy in the cosmic microwave background (CMB). In particular we consider whether the observed low CMB quadrupole could more generally signal odd…

Astrophysics · Physics 2015-06-24 Kate Land , Joao Magueijo

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 calculate the CMB anisotropy power spectrum of a closed universe for large angle (i.e., low $l$) due to a scale invariant fluctuation of primordial universe by considering the spherical harmonics for 3-sphere. In particular, contrary to…

General Relativity and Quantum Cosmology · Physics 2020-12-16 Youngsub Yoon

Recent detections of cosmic microwave background (CMB) anisotropy at half-degree angular scales show considerable scatter in the reported amplitude even at similar angular resolution. We use Monte Carlo techniques to simulate the current…

Astrophysics · Physics 2007-05-23 A. Kogut , G. Hinshaw

Assuming that the cosmological principle holds, Maartens, Ellis and Stoeger (MES) recently constructed a detailed scheme linking anisotropies in the cosmic background radiation (CMB) with anisotropies and inhomogeneities in the large scale…

Astrophysics · Physics 2008-12-01 William Stoeger , Marcelo Araujo , Tim Gebbie

We examine the extent to which galactic and extragalactic foregrounds can hamper the detection of primordial Cosmic Microwave Background (CMB) anisotropies. We limit our discussion to intermediate angular scales, $10^{\prime}\lsim \theta…

Astrophysics · Physics 2009-09-25 L. Toffolatti

In this letter we will show that, contrary to what is widely believed, an almost isotropic cosmic microwave background (CMB) temperature does not imply that the universe is ``close to a Friedmann-Lemaitre universe''. There are two important…

Astrophysics · Physics 2009-10-31 U. S. Nilsson , C. Uggla , J. Wainwright , W. C. Lim

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

Techniques for computing the CMBR anisotropy from simulations of topological defects are discussed with an eye to getting as much information from a simulation as possible. Here we consider the practical details of which sums and…

Astrophysics · Physics 2007-05-23 Albert Stebbins , Scott Dodelson

We point out that the recent WMAP findings of a suppressed large scale power in the Cosmic Microwave Background anisotropy power spectrum, if of cosmological origin, make the case for a new cosmic coincidence problem.The observed…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alessandro Melchiorri , Laura Mersini-Houghton

We discuss the effect of the time evolution of extra dimensions on CMB anisotropies and large-scale structure formation. We study the impact of scalar fields in a low-energy effective description of a general class of brane world models on…

Astrophysics · Physics 2009-11-07 C. S. Rhodes , C. van de Bruck , Ph. Brax , A. C. Davis

The expansion of the universe may be observed in ``realtime'' by measuring changes in the patterns of the anisotropy in the CMB. As the universe ages, the surface of decoupling--or the CMB photosphere--moves away from us and samples a…

Astrophysics · Physics 2009-11-13 S. Lange , L. Page

We study CMB in the nonstandard background cosmology recently investigated. Using the previously calculated first order metric perturbations we discuss the Sachs-Wolfe and the integrated Sachs-Wolfe effects. We show how small-multipole CMB…

General Physics · Physics 2019-08-06 Gunter Scharf