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The recent WMAP data represents a milestone in cosmology and helps constrain cosmological parameters with unprecedented accuracy. In this work we combine the WMAP data with previous CMB anisotropy measurements at smaller angular scales to…

Astrophysics · Physics 2015-06-24 C. J. Odman

In this paper we show how effects from small scales can enter the angular-redshift power spectrum $C_\ell(z,z')$. In particular, we show that spectroscopic surveys with high redshift resolution are already affected on large angular scales,…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 William L. Matthewson , Ruth Durrer

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

We introduce a class of models in which statistical isotropy is broken spontaneously in the CMB by a non-linear response to long-wavelength fluctuations in a mediating field. These fluctuations appear as a gradient locally and pick out a…

Astrophysics · Physics 2008-11-26 Christopher Gordon , Wayne Hu , Dragan Huterer , Tom Crawford

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.…

The Doppler peaks (Sacharov peaks) in the angular power spectrum of the cosmic microwave background anisotropies, are mainly due to coherent oscillations in the baryon radiation plasma before recombination. Here we present a calculation of…

Astrophysics · Physics 2009-10-28 Ruth Durrer , Alejandro Gangui , Mairi Sakellariadou

We investigate the modulation of turbulence caused by the presence of finite-size dispersed particles. Bluff (isotropic) spheres vs slender (anisotropic) fibers are considered to understand the influence of the object shape on altering the…

Fluid Dynamics · Physics 2022-11-09 Stefano Olivieri , Ianto Cannon , Marco E. Rosti

We investigate the ability to constrain oscillatory features in the primordial power spectrum using current and future cosmic microwave background observations. In particular, we study the observability of an oscillation arising from…

Astrophysics · Physics 2011-05-12 Takemi Okamoto , Eugene A. Lim

We calculate the expected angular power spectrum of the temperature fluctuations in the microwave background radiation (MBR) generated in the quasi-steady state cosmology (QSSC). The paper begins with a brief description of how the…

Astrophysics · Physics 2009-11-07 J. V. Narlikar , R. G. Vishwakarma , Amir Hajian , Tarun Souradeep , G. Burbidge , F. Hoyle

In this thesis we investigate several aspects related to the theory of fluctuations in the Cosmic Microwave Background. We develop a new algorithm to calculate the angular power spectrum of the anisotropies which is two orders of magnitude…

Astrophysics · Physics 2007-05-23 Matias Zaldarriaga

We examine the impact of different anisotropic relics on inflation, in particular the predictions on the density perturbations. These relics can be the source of the large scale anomalies in the cosmic microwave background. There are two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Xingang Chen , Razieh Emami , Hassan Firouzjahi , Yi Wang

We present the largest low frequency (120~MHz) arcminute resolution image of the radio synchrotron background (RSB) to date, and its corresponding angular power spectrum of anisotropies (APS) with angular scales ranging from $3^\circ$ to…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 F. J. Cowie , A. R. Offringa , B. K. Gehlot , J. Singal , S. Heston , S. Horiuchi , D. M. Lucero

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

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…

Astrophysics · Physics 2011-04-15 Ruth Durrer

We investigate the dependence of large angular scale cosmic microwave background anisotropies on various initial conditions, including both adiabatic and isocurvature perturbations and the initial power law index $n$, in a variety of…

Astrophysics · Physics 2009-10-22 Naoshi Sugiyama , Joseph Silk

We argue that the lack of power exhibited by cosmic microwave background (CMB) anisotropies at large angular scales might be linked to the onset of inflation. We highlight observational features and theoretical hints that support this view,…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 A. Gruppuso , A. Sagnotti

It has been argued that the large-angle cosmic microwave background anisotropy has anomalies at 3-sigma level. We review various proposed ideas to explain the origin of the anomalies and discuss how we can constrain the proposed models…

Astrophysics · Physics 2007-10-15 Kaiki Taro Inoue

We investigate how the qualitative structure of Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy is affected by basic assumptions going into theories of structure formation. We define the concepts of…

Astrophysics · Physics 2010-04-08 Joao Magueijo , Andreas Albrecht , Pedro Ferreira , David Coulson

We investigate the contribution of cosmic string loops to the Cosmic Microwave Background (CMB) anisotropies. This is done by extending the Unconnected Segment Model (USM) to include the contribution of the cosmic string loops created…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 I. Yu. Rybak , L. Sousa

In this work, we develop a novel formalism to include the effect of electron density fluctuations at ultra small scales (well below the sound horizon at last scattering) on the observed anisotropies of the Cosmic Microwave Background (CMB).…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-29 Jens Chluba , Geoffrey Vasil , Richard Battye