English
Related papers

Related papers: The Fine Structure Constant and the CMB Damping Sc…

200 papers

The angular two-point correlation function of the temperature of the cosmic microwave background (CMB), as inferred from nearly all-sky maps, is very close to zero on large angular scales. A statistic invented to quantify this feature,…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-04 Robert Knight , Lloyd Knox

Observations show that the Cosmic Microwave Background (CMB) contains tiny variations at the 10^{-5} level around its black-body equilibrium temperature. The detection of these temperature fluctuations provides to modern Cosmology evidence…

Astrophysics · Physics 2015-06-24 Armando Bernui

In this work we investigate the effects of the primordial magnetic fields on cosmic microwave background anisotropies (CMB). Based on cosmological magnetohydrodynamic (MHD) simulations we calculate the CMB anisotropy spectra and…

Astrophysics · Physics 2009-11-13 Hiroyuki Tashiro , Naoshi Sugiyama , Robi Banerjee

The so-called shift parameter is related to the position of the first acoustic peak in the power spectrum anisotropies of the cosmic microwave background (CMB) anisotropies. It is an often used quantity in simple tests of dark energy…

Astrophysics · Physics 2009-11-13 Oystein Elgaroy , Tuomas Multamaki

We investigate the statistical anisotropy and Gaussianity of temperature fluctuations of Cosmic Microwave Background radiation (CMB) data from {\it Wilkinson Microwave Anisotropy Probe} survey, using the multifractal detrended fluctuation…

Astrophysics · Physics 2011-08-04 M. Sadegh Movahed , F. Ghasemi , Sohrab Rahvar , M. Reza Rahimi Tabar

Searches for spacetime variations of fundamental constants have entered an era of unprecedented precision. New, high quality quasar spectra require increasingly refined analytic methods. In this article, a continuation in a series to…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-03 John K. Webb , Chung-Chi Lee

Detailed study of the scalar and tensor perturbation spectra can provide much information about the primordial fluctuation-generator, be it inflation or something else. The tensor perturbation spectrum may be observable through its…

Astrophysics · Physics 2007-05-23 L. Knox

Current cosmological constraints from Cosmic Microwave Background (CMB) anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination,…

Astrophysics · Physics 2009-02-23 Silvia Galli , Rachel Bean , Alessandro Melchiorri , Joseph Silk

Recent analysis of the WMAP and Planck data have shown the presence of a dip and a bump in the spectrum of primordial perturbations at the scales $k=0.002$ Mpc${}^{-1}$ and $k=0.0035$ Mpc${}^{-1}$ respectively. We analyze for the first time…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Alexander Gallego Cadavid , Antonio Enea Romano , Stefano Gariazzo

We present a significant update of the constraints on the Abelian Higgs cosmic string tension by cosmic microwave background (CMB) data, enabled both by the use of new high-resolution CMB data from suborbital experiments as well as the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 J. Urrestilla , N. Bevis , M. Hindmarsh , M. Kunz

The locations and amplitudes of three acoustic peaks and two dips in the last releases of the Boomerang, MAXIMA and DASI measurements of the cosmic microwave background (CMB) anisotropy power spectra as well as their statistical confidence…

Astrophysics · Physics 2009-11-07 R. Durrer , B. Novosyadlyj , S. Apunevych

The cosmic microwave background (CMB) temperature anisotropies exhibit a large-scale dipolar power asymmetry. To determine whether this is due to a real, physical modulation or is simply a large statistical fluctuation requires the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 D. Contreras , J. P. Zibin , D. Scott , A. J. Banday , K. M. Górski

The CMB is perhaps the cleanest cosmological observable. Given a cosmology model, the angular spectrum of the CMB can be computed to percent accuracy. On the observational side, as far as we know, there is little that stands in the way…

Astrophysics · Physics 2007-05-23 L. A. Page

Weak lensing distortion of the background cosmic microwave background (CMB) temperature and polarization patterns by the foreground density fluctuations is well studied in the literature. We discuss the gravitational lensing modification to…

Astrophysics · Physics 2009-11-11 Chao Li , Asantha Cooray

Measurements of cosmic microwave background (CMB) anisotropies constrain isocurvature fluctuations between photons and non-relativistic particles to be sub-dominant to adiabatic fluctuations. Perturbations in the relative number densities…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-09 Daniel Grin , Olivier Doré , Marc Kamionkowski

We explore the qualitative changes that would occur if the amplitude Q ~ 10^{-5} of cosmological density fluctuations were different. If is less than about 10^{-6}, the cosmological objects that form would have so low virial temperatures…

Astrophysics · Physics 2009-10-07 Max Tegmark , Martin Rees

We investigate the stochasticity in temperature fluctuations in the cosmic microwave background (CMB) radiation data from {\it Wilkinson Microwave Anisotropy Probe}. We show that the angular fluctuations of the temperature is a Markov…

Since the discovery of the Cosmic Microwave Background (CMB) in 1965, characterization of the CMB anisotropy angular power spectrum has become somewhat of a holy grail for experimental cosmology. Because CMB anisotropy measurements are…

Astrophysics · Physics 2017-08-23 A. D. Miller

Cosmic microwave background (CMB) anisotropies probe the primordial density field at the edge of the observable Universe. There is a limiting precision (``cosmic variance'') with which anisotropies can determine the amplitude of primordial…

Astrophysics · Physics 2016-08-25 Marc Kamionkowski , Abraham Loeb

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Duncan Hanson , Antony Lewis