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Anisotropies in the Cosmic Microwave Background (CMB) contain a wealth of information about the past history of the universe and the present values of cosmological parameters. I ouline some of the theoretical advances of the last few years.…

Astrophysics · Physics 2007-05-23 Scott Dodelson

Measurements of the cosmic microwave background (CMB) temperature anisotropies have revealed a dipolar asymmetry in power at the largest scales, in apparent contradiction with the statistical isotropy of standard cosmological models. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 D. Contreras , J. Hutchinson , A. Moss , D. Scott , J. P. Zibin

A recently proposed mechanism for large-scale structure in string cosmology --based on massless axionic seeds-- is further analyzed and extended to the acoustic-peak region. Existence, structure, and normalization of the peaks turn out to…

Astrophysics · Physics 2009-10-31 A. Melchiorri , F. Vernizzi , R. Durrer , G. Veneziano

We perform a multiparameter likelihood analysis to compare measurements of the cosmic microwave background (CMB) power spectra with predictions from models involving cosmic strings. Adding strings to the standard case of a primordial…

Astrophysics · Physics 2008-11-26 Neil Bevis , Mark Hindmarsh , Martin Kunz , Jon Urrestilla

In this paper we present a complete computation of the Cosmic Microwave Background (CMB) anisotropies up to third order from gravitational perturbations accounting for scalar, vector and tensor perturbations. We then specify our results to…

Astrophysics · Physics 2008-11-26 G. D'Amico , N. Bartolo , S. Matarrese , A. Riotto

We compute maps of CMB temperature fluctuations seeded by cosmic strings using high resolution simulations of cosmic strings in a Friedmann-Robertson-Walker universe. We create full-sky, 18-degree and 3-degree CMB maps, including the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-23 M. Landriau , E. P. S. Shellard

We study the problem of searching for cosmic string signal patterns in the present high resolution and high sensitivity observations of the Cosmic Microwave Background (CMB). This article discusses a technique capable of recognizing…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 E. Jeong , Carlo Baccigalupi , G. F. Smoot

The COBE satellite's maps of the cosmic microwave background (CMB) anisotropy do not have the resolution to discriminate between theories of cosmic structure formation based on inflation, and those based on field ordering following a…

High Energy Physics - Phenomenology · Physics 2009-09-25 David Coulson , Ue-Li Pen , Neil Turok

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.…

In recent years the goal of estimating different cosmological parameters precisely has set new challenges in the effort to accurately measure the angular power spectrum of CMB. This has required removal of foreground contamination as well…

Astrophysics · Physics 2008-11-26 Rajib Saha , Simon Prunet , Pankaj Jain , Tarun Souradeep

We examine variations in the equation of state of the cosmic string portion of the cosmological fluid which lead to perturbations of the background matter density. These fluctuations in the equation of state are due to variations in the…

Astrophysics · Physics 2010-01-06 Pedro Avelino , Robert Caldwell

Cross-correlating the lensing signals of galaxies and comic microwave background (CMB) fluctuations is expected to provide valuable cosmological information. In particular it may help tighten constraints on parameters describing the…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-14 Philipp M. Merkel , Bjoern Malte Schaefer

Characterizing the physical properties of the stochastic gravitational waves background (SGWB) is a key step towards identifying the nature of its possible origin. We focus our analysis on SGWB anisotropies. The existence of a non-trivial…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-14 Peter Adshead , Niayesh Afshordi , Emanuela Dimastrogiovanni , Matteo Fasiello , Eugene A. Lim , Gianmassimo Tasinato

With the advent of a new generation of cosmological experiments that will provide high-precision measurements of the cosmic microwave background (CMB) and galaxies in the large-scale structure, it is pertinent to examine the potential of…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-27 Shu-Fan Chen , Hayden Lee , Cora Dvorkin

Cosmic microwave background (CMB) observations provide in principle a high-precision test of models which are motivated by M theory. We set out the framework of a program to compute the tensor anisotropies in the CMB that are generated in…

Astrophysics · Physics 2009-11-07 Bernard Leong , Anthony Challinor , Roy Maartens , Anthony Lasenby

We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis…

Astrophysics · Physics 2009-11-10 Fabio Giovi , Carlo Baccigalupi , Francesca Perrotta

We study Gravitational Waves (GWs) in the context of Massive Gravity, an extension to General Relativity (GR) where the fluctuations of the metric have a nonzero mass, and specifically investigate the effect of the tensor modes on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Dennis Bessada , Oswaldo D. Miranda

We present a 1+3 covariant discussion of the contribution of gravitational waves to the anisotropy of the CMB in an almost-Friedmann-Robertson-Walker universe. Our discussion is based in the covariant approach to perturbations in cosmology,…

Astrophysics · Physics 2014-10-13 Anthony Challinor

We present the first CMB power spectra from numerical simulations of the global O(N) linear $\sigma$-model with N = 2,3, which have global strings and monopoles as topological defects. In order to compute the CMB power spectra we compute…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-28 Asier Lopez-Eiguren , Joanes Lizarraga , Mark Hindmarsh , Jon Urrestilla

The cosmic microwave background (CMB) is gravitationally lensed by large-scale structure, which distorts observations of the primordial anisotropies in any given direction. Averaged over the sky, this important effect is routinely modelled…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 G. Fabbian , J. Carron , A. Lewis , M. Lembo