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In cosmological models where local cosmic strings are formed at the end of a period of inflation, the perturbations are seeded both by the defects and by the quantum fluctuations. In a subset of these models, for example those based on…

Astrophysics · Physics 2009-10-30 Carlo Contaldi , Mark Hindmarsh , Joao Magueijo

Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-29 Maresuke Shiraishi , David F. Mota , Angelo Ricciardone , Frederico Arroja

We propose a multi-scale edge-detection algorithm to search for the Gott-Kaiser-Stebbins imprints of a cosmic string (CS) network on the Cosmic Microwave Background (CMB) anisotropies. Curvelet decomposition and extended Canny algorithm are…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-12 A. Vafaei Sadr , S. M. S. Movahed , M. Farhang , C. Ringeval , F. R. Bouchet

Cosmic microwave background (CMB) anisotropy may result from both scalar and tensor perturbations. For a sufficiently narrow range of angular scales, CMB perturbations can be characterized by four parameters. Results from the Cosmic…

Astrophysics · Physics 2009-10-22 Scott Dodelson , Lloyd Knox , Edward W. Kolb

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

Fluctuations in the cosmic microwave background (CMB) contain information which has been pivotal in establishing the current cosmological model. These data can also be used to test well-motivated additions to this model, such as cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-13 Stephen M. Feeney , Matthew C. Johnson , Daniel J. Mortlock , Hiranya V. Peiris

We emphasize that the estimation of cosmological parameters from cosmic microwave background (CMB) anisotropy data, such as the recent high resolution maps from BOOMERanG and MAXIMA-1, requires assumptions about the primordial spectra. The…

Astrophysics · Physics 2009-10-31 Jerome Martin , Alain Riazuelo , Dominik J. Schwarz

Gaussianity of the cosmological perturbations in the universe is one of the key predictions of standard inflation, but it is violated by other models of structure formation such as topological defects. We present the first test of the…

In a recent publication, we used the data from WMAP and SDSS to constrain the primordial perturbations and to predict the B-mode polarization sourced by cosmic string networks. We have been alerted by A. Slosar to the existence of errors in…

Astrophysics · Physics 2007-05-23 Levon Pogosian , Ira Wasserman , Mark Wyman

One of the major predictions of inflation is the existence of a stochastic background of cosmological gravitational waves (GW). These gravitational waves can induce significant temperature anisotropies in the Cosmic Microwave Background…

Astrophysics · Physics 2009-11-07 Alessandro Melchiorri , Carolina Odman

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 anisotropies of the cosmic microwave background (CMB) are computed for the half-turn space E_2 which represents a compact flat model of the Universe, i.e. one with finite volume. This model is inhomogeneous in the sense that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 R. Aurich , S. Lustig

We present in detail the convolutional neural network used in our previous work to detect cosmic strings in cosmic microwave background (CMB) temperature anisotropy maps. By training this neural network on numerically generated CMB…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-15 Razvan Ciuca , Oscar F. Hernández , Michael Wolman

The latest Planck results show a power deficit in the temperature anisotropies near $\ell \approx 20$ in the cosmic microwave background (CMB). This observation can hardly be explained within the standard inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-05 Yi-Fu Cai , Elisa G. M. Ferreira , Bin Hu , Jerome Quintin

Cosmic Microwave Background (CMB) anisotropy encodes a lot of information about our Universe. In this paper we take the ground-based CMB observations (GCMB), including the South Pole Telescope (SPT), SPTpol and the Atacama Cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 Ke Wang , Qing-Guo Huang

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

If current ideas about unified field theories are correct, macroscopic cosmic defects may well exist. The observation of such an entity would have enormous significance for our understanding of fundamental physics. This paper points out a…

Astrophysics · Physics 2009-10-28 Neil Turok

Using an analytic model we show that the predictions of the cosmic string model for the peculiar velocities and the microwave background (MBR) anisotropy depend on similar combinations of string evolution parameters. Normalizing from the…

High Energy Physics - Phenomenology · Physics 2009-10-22 L. Perivolaropoulos , T. Vachaspati

We study the cosmic microwave background (CMB) anisotropy due to spherically symmetric nonlinear structures in flat universes with dust and a cosmological constant. By modeling a time-evolving spherical compensated void/lump by…

Astrophysics · Physics 2009-02-20 Nobuyuki Sakai , Kaiki Taro Inoue

The Cosmic Microwave Background (CMB) fluctuations at very small angular scales (less than $10'$) induced by matter sources are computed in a simplified way. The result corrects a previous formula appearing in the literature. The small…

Astrophysics · Physics 2011-05-10 Mark Hindmarsh