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The Cosmic Microwave Background (CMB) bispectrum of the temperature anisotropies induced by a network of cosmic strings is derived for small angular scales, under the assumption that the principal cause of temperature fluctuations is the…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Mark Hindmarsh , Christophe Ringeval , Teruaki Suyama

We study the effect of weak lensing by cosmic (super-)strings on the higher-order statistics of the cosmic microwave background (CMB). A cosmic string segment is expected to cause weak lensing as well as an integrated Sachs-Wolfe (ISW)…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 Daisuke Yamauchi , Yuuiti Sendouda , Keitaro Takahashi

Using analytical methods and Monte Carlo simulations, we analyze new statistics designed to detect isolated step-like discontinuities which are coherent over large areas of Cosmic Microwave Background (CMB) pixel maps. Such coherent…

Astrophysics · Physics 2011-05-10 L. Perivolaropoulos

We use the publicly available code CMBFAST as modified by L. Pogosian and T. Vachaspati to simulate the effects of wiggly cosmic strings on the Cosmic Microwave Background (CMB). Using the modified CMBFAST code which takes into account…

Astrophysics · Physics 2011-05-10 N. Simatos , L. Perivolaropoulos

We provide an analytical expression for the trispectrum of the Cosmic Microwave Background (CMB) temperature anisotropies induced by cosmic strings. Our result is derived for the small angular scales under the assumption that the…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Mark Hindmarsh , Christophe Ringeval , Teruaki Suyama

We examine the two-point correlation function of local maxima in temperature fluctuations at the last scattering surface when this stochastic field is modified by the additional fluctuations produced by straight cosmic strings via the…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-15 M. Sadegh Movahed , B. Javanmardi , Ravi K. Sheth

Using analytical methods and Monte Carlo simulations, we analyze a new statistic designed to detect isolated step-like discontinuities which are coherent over large areas of Cosmic Microwave Background (CMB) pixel maps. Such coherent…

Astrophysics · Physics 2007-05-23 Leandros Perivolaropoulos

We explore the use of random forest and gradient boosting, two powerful tree-based machine learning algorithms, for the detection of cosmic strings in maps of the cosmic microwave background (CMB), through their unique Gott-Kaiser-Stebbins…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-12 A. Vafaei Sadr , M. Farhang , S. M. S. Movahed , B. Bassett , M. Kunz

We simulate the anisotropy in the cosmic microwave background (CMB) induced by cosmic strings. By numerically evolving a network of cosmic strings we generate full-sky CMB temperature anisotropy maps. Based on $192$ maps, we compute the…

Astrophysics · Physics 2008-11-26 B. Allen , R. R. Caldwell , E. P. S. Shellard , A. Stebbins , S. Veeraraghavan

We study the impact of kinks on the cosmic microwave background (CMB) anisotropies generated by cosmic string networks. To do so, we extend the Unconnected Segment Model to describe the stress-energy tensor of a network of cosmic strings…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-02 Rodrigo P. Silva , Lara Sousa , Ivan Yu. Rybak

We develop a method of constraining the cosmic string tension $G\mu$ which uses the Canny edge detection algorithm as a means of searching CMB temperature maps for the signature of the Kaiser-Stebbins effect. We test the potential of this…

Astrophysics · Physics 2009-11-19 Andrew Stewart , Robert Brandenberger

An unexpected distribution of temperatures in the CMB could be a sign of new physics. In particular, the existence of cosmic defects could be indicated by temperature discontinuities via the Kaiser-Stebbins effect. In this paper, we show…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Jude Bowyer , Andrew H. Jaffe

We explore the large angular scale temperature anisotropies in the cosmic microwave background (CMB) due to homogeneous local dust-filled voids in a flat Friedmann-Robertson-Walker universe with a cosmological constant. In comparison with…

Astrophysics · Physics 2008-11-26 Kaiki Taro Inoue , Joseph Silk

We use Nambu-Goto numerical simulations to compute the cosmic microwave background (CMB) temperature anisotropies induced at arcminute angular scales by a network of cosmic strings in a Friedmann-Lemaitre-Robertson-Walker (FLRW) expanding…

We apply new statistical tests on the four year 53 GHz DMR data and show that there is significant probability for the existence of coherent temperature discontinuities hidden in the CMB maps around the Galactic Poles. Comparing Monte Carlo…

Astrophysics · Physics 2007-05-23 L. Perivolaropoulos , N. Simatos

The cosmic string scenario in an open universe is developed -- including the equations of motion, a model of network evolution, the large angular scale CMB temperature anisotropy, and the power spectrum of density fluctuations produced by…

Astrophysics · Physics 2009-10-30 P. P. Avelino , R. R. Caldwell , C. J. A. P. Martins

Extending the Kaiser-Stebbins mechanism we propose here a method for detecting relics of topological defects such as cosmic strings based on lens-induced small-scale B-type polarization in the CMB. Models of inflation, in which large scale…

Astrophysics · Physics 2009-10-31 K. Benabed , F. Bernardeau

I review recent progress towards a detailed understanding of the power spectrum of cosmic string perturbations induced on the Microwave Background (CMB). The use of a simple analytic model allows to include important effects that have not…

Astrophysics · Physics 2007-05-23 Leandros Perivolaropoulos

We construct a simple analytical model to study the effects of cosmic strings on the microwave background radiation. Our model is based on counting random multiple impulses inflicted on photon trajectories by the string network between the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Leandros Perivolaropoulos

Motivated by the fact that cosmological perturbations of inflationary quantum origin were born Gaussian, the search for non-Gaussianities in the cosmic microwave background (CMB) anisotropies is considered as the privileged probe of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Christophe Ringeval
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