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Cosmic strings are a well-motivated extension to the standard cosmological model and could induce a subdominant component in the anisotropies of the cosmic microwave background (CMB), in addition to the standard inflationary component. The…

天体物理仪器与方法 · 物理学 2017-09-18 J. D. McEwen , S. M. Feeney , H. V. Peiris , Y. Wiaux , C. Ringeval , F. R. Bouchet

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…

天体物理学 · 物理学 2008-11-26 B. Allen , R. R. Caldwell , E. P. S. Shellard , A. Stebbins , S. Veeraraghavan

Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings…

宇宙学与河外天体物理 · 物理学 2016-03-09 Christophe Ringeval , Daisuke Yamauchi , Jun'ichi Yokoyama , Francois R. Bouchet

We present the first ever calculation of cosmic microwave background CMB anisotropy power spectra from semilocal cosmic strings, obtained via simulations of a classical field theory. Semilocal strings are a type of non-topological defect…

天体物理学 · 物理学 2009-06-23 Jon Urrestilla , Neil Bevis , Mark Hindmarsh , Martin Kunz , Andrew R. Liddle

Recent measurements of the cosmic microwave background (CMB) anisotropies by BOOMERANG and MAXIMA collaborations have tightened the observational constraints on theories of structure formation. They disagree with the predictions of…

天体物理学 · 物理学 2009-10-31 Levon Pogosian

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…

天体物理学 · 物理学 2008-11-26 Aurélien A. Fraisse , Christophe Ringeval , David N. Spergel , François R. Bouchet

By actively distorting the Cosmic Microwave Background (CMB) over our past light cone, cosmic strings are unavoidable sources of non-Gaussianity. Developing optimal estimators able to disambiguate a string signal from the primordial type of…

宇宙学与河外天体物理 · 物理学 2012-08-22 Christophe Ringeval , Francois R. Bouchet

Cosmic strings are one-dimensional topological defects which could have been formed in the early stages of our Universe. They triggered a lot of interest, mainly for their cosmological implications: they could offer an alternative to…

高能物理 - 理论 · 物理学 2009-11-11 Mairi Sakellariadou

Cosmic strings are topological defects possibly formed in the early Universe, which may be observable due to their gravitational effects on the cosmic microwave background radiation or gravitational wave experiments. To this effect it is…

宇宙学与河外天体物理 · 物理学 2017-03-01 R. P. L. Azevedo , C. J. A. P. Martins

We have computed an estimate of the angular power spectrum of the Cosmic Microwave Background (CMB) induced by cosmic strings on angular scales $>~ 15'$, using a numerical simulation of a cosmic string network; and decomposed this pattern…

天体物理学 · 物理学 2016-08-30 B. Allen , R. R. Caldwell , S. Dodelson , L. Knox , E. P. S. Shellard , A. Stebbins

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…

宇宙学与河外天体物理 · 物理学 2021-07-14 I. Yu. Rybak , L. Sousa

We briefly review certain aspects of cosmic microwave background anisotropies as generated in passive and active models of structure formation. We then focus on cosmic strings based models and discuss their status in the light of current…

天体物理学 · 物理学 2009-11-07 Alejandro Gangui , Levon Pogosian , Serge Winitzki

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…

宇宙学与河外天体物理 · 物理学 2018-10-12 A. Vafaei Sadr , S. M. S. Movahed , M. Farhang , C. Ringeval , F. R. Bouchet

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…

宇宙学与河外天体物理 · 物理学 2014-11-20 E. Jeong , Carlo Baccigalupi , G. F. Smoot

Cosmic Microwave Background (CMB) has been a cornerstone in many cosmology experiments and studies since it was discovered back in 1964. Traditional computational models like CAMB that are used for generating CMB temperature anisotropy maps…

宇宙学与河外天体物理 · 物理学 2019-12-02 Amit Mishra , Pranath Reddy , Rahul Nigam

Because cosmic superstrings generically form junctions and gauge theoretic strings typically do not, junctions may provide a signature to distinguish between cosmic superstrings and gauge theoretic cosmic strings. In cosmic microwave…

宇宙学与河外天体物理 · 物理学 2014-11-20 Rebecca J. Danos , Robert H. Brandenberger

Cosmic string networks generate cosmological perturbations actively throughout the history of the universe. Thus, the string sourced anisotropy of the cosmic microwave background is not affected by Silk damping as much as the anisotropy…

天体物理学 · 物理学 2010-04-15 Levon Pogosian , S. -H. Henry Tye , Ira Wasserman , Mark Wyman

We use the emulation framework CosmoPower to construct and publicly release neural network emulators of cosmological observables, including the Cosmic Microwave Background (CMB) temperature and polarization power spectra, matter power…

宇宙学与河外天体物理 · 物理学 2023-03-06 Boris Bolliet , Alessio Spurio Mancini , J. Colin Hill , Mathew Madhavacheril , Hidde T. Jense , Erminia Calabrese , Jo Dunkley

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…

宇宙学与河外天体物理 · 物理学 2019-03-15 Razvan Ciuca , Oscar F. Hernández , Michael Wolman

An algorithm is proposed for denoising the signal induced by cosmic strings in the cosmic microwave background (CMB). A Bayesian approach is taken, based on modeling the string signal in the wavelet domain with generalized Gaussian…

天体物理学 · 物理学 2009-11-16 D. K. Hammond , Y. Wiaux , P. Vandergheynst
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