English
Related papers

Related papers: Statistical Isotropy violation of the CMB brightne…

200 papers

The tremendous experimental progress in cosmic microwave background (CMB) temperature and polarization anisotropy studies over the last few years has helped establish a standard paradigm for cosmology at intermediate epochs and has…

Astrophysics · Physics 2011-05-12 Wayne Hu

There currently exist many observations which are not consistent with the cosmological principle. We review these observations with a particular emphasis on those relevant for Square Kilometre Array (SKA). In particular, several different…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-03 Shamik Ghosh , Pankaj Jain , Gopal Kashyap , Rahul Kothari , Sharvari Nadkarni-Ghosh , Prabhakar Tiwari

We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

We study the anisotropy of the cosmic microwave background (CMB) in cold and mixed dark matter (CDM and MDM) models, with non scale-invariant primordial power spectra (i.e. $n \neq 1$) and a late, sudden reionization of the intergalactic…

Search for the statistical anisotropy in the CMB data is a powerful tool for constraining models of the early Universe. In this paper we focus on the recently proposed cosmological scenario with conformal rolling. We consider two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 S. R. Ramazanov , G. I. Rubtsov

The CMB angular temperature fluctuations observed by COBE and WMAP enable us to place a lower limit on the spectral distortions of the CMB at any angular scale. These distortions are connected with the simple fact, that the superposition of…

Astrophysics · Physics 2009-11-10 J. Chluba , R. A. Sunyaev

The Cosmological Principle states that the universe is statistically isotropic and homogeneous on large length scales, typically $\gtrsim 70$Mpc. A detection of significant deviation would help us falsify the simplest models of inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Bhuwan Joshi , Rahul Kothari

We present final results on the angular power spectrum of total intensity anisotropies in the CMB from the CBI. Our analysis includes all primordial anisotropy data collected between January 2000 and April 2005, and benefits significantly…

The lack of power of large--angle CMB anisotropies is known to increase its statistical significance at higher Galactic latitudes, where a string--inspired pre--inflationary scale $\Delta$ can also be detected. Considering the Planck 2015…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-13 A. Gruppuso , N. Kitazawa , M. Lattanzi , N. Mandolesi , P. Natoli , A. Sagnotti

The Standard Inflationary model predicts an isotropic distribution of the Cosmic Microwave Background temperature fluctuations. Detection of deviations from statistical isotropy would call for a revision of the physics of the early…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Laura Cayon

In the light of the recent Boomerang and Maxima observations of the CMB which show an anomalously low second acoustic peak, we reexamine the prediction by Adams et al (1997) that this would be the consequence of a 'step' in the primordial…

Astrophysics · Physics 2019-08-17 J. Barriga , E. Gaztanaga , M. G. Santos , S. Sarkar

The most general homogeneous and isotropic statistical ensemble of linear scalar perturbations which are regular at early times, in a universe with only photons, baryons, neutrinos, and a cold dark matter (CDM) component, is described by a…

Astrophysics · Physics 2009-10-31 Martin Bucher , Kavilan Moodley , Neil Turok

The advent of high signal-to-noise cosmic microwave background (CMB) anisotropy experiments has allowed detailed studies on the power spectrum of temperature fluctuations. The existence of acoustic oscillations in the anisotropy power…

Astrophysics · Physics 2009-11-07 Asantha Cooray

We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) using data from the South Pole Telescope (SPT). The data consist of 790 square degrees of sky observed at 150 GHz during 2008 and 2009. Here we…

Although the new era of high precision cosmology of the cosmic microwave background (CMB) radiation improves our knowledge to understand the infant as well as the presentday Universe, it also leads us to question the main assumption of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Esra Russell , Can Battal Kilinc , Oktay K. Pashaev

Secondary anisotropies of the cosmic microwave background (CMB) can be detected by using the cross-correlation between the large-scale structure (LSS) and the CMB temperature fluctuations. In such studies, chance correlations of primordial…

Astrophysics · Physics 2009-02-26 Mona Frommert , Torsten A. Ensslin

Through analytic techniques verified by numerical calculations, we establish general relations between the matter and cosmic microwave background (CMB) power spectra and their dependence on cosmological parameters on small scales.…

Astrophysics · Physics 2009-07-22 Wayne Hu , Naoshi Sugiyama

It is assumed that the dark energy observed today is frozen as a result of a phase transition involving the source of that energy. Postulating that the dark energy de-coherence which results from this phase transition drives statistical…

Astrophysics · Physics 2009-11-10 James V. Lindesay , H. Pierre Noyes , E. D. Jones

The standard model of cosmology predicts a statistically isotropic (SI) CMB sky. However, the SI violation signals are always present in an observed sky-map. Different cosmological artifacts, measurement effects and unavoidable effects…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Santanu Das

Global, symmetry-breaking phase transitions in the early universe can generate scaling seed networks which lead to metric perturbations. The acoustic waves in the photon-baryon plasma sourced by these metric perturbations, when Silk damped,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Mustafa A. Amin , Daniel Grin