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相关论文: Large Angular Scale CMB Anisotropy Induced by Cosm…

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We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to the predictions of cosmic strings. We use an analytic model for the $\Delta T/T$ power spectrum that is based on our previous…

高能物理 - 唯象学 · 物理学 2009-10-22 David P. Bennett , Albert Stebbins , Francois R. Bouchet

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 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

We find the constraints from WMAP and SDSS data on the fraction of cosmological fluctuations sourced by local cosmic strings using a Markov Chain Monte Carlo (MCMC) analysis. In addition to varying the usual 6 cosmological parameters and…

天体物理学 · 物理学 2014-10-13 Mark Wyman , Levon Pogosian , Ira Wasserman

Using an analytical model for the string network we show that the kurtosis of cosmic microwave background (CMB) temperature gradient maps is a good statistic to distinguish between the cosmic string model and inflationary models of…

天体物理学 · 物理学 2011-05-10 R. Moessner , L. Perivolaropoulos , R. Brandenberger

In this work we study the imprints of a primordial cosmic string on inflationary power spectrum. Cosmic string induces two distinct contributions on curvature perturbations power spectrum. The first type of correction respects the…

宇宙学与河外天体物理 · 物理学 2017-07-19 Sadra Jazayeri , Alireza Vafaei Sadr , Hassan Firouzjahi

In the inflationary scenarios suggested by string theory, the vacuum fluctuations of the electromagnetic field can be amplified by the time-evolution of the dilaton background, and can grow large enough to explain both the origin of the…

天体物理学 · 物理学 2010-01-06 M. Gasperini , M. Giovannini , G. Veneziano

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

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…

宇宙学与河外天体物理 · 物理学 2023-08-02 Rodrigo P. Silva , Lara Sousa , Ivan Yu. Rybak

We compute maps of CMB temperature fluctuations seeded by cosmic strings using high resolution simulations of cosmic strings in a Friedmann-Robertson-Walker universe. We create full-sky, 18-degree and 3-degree CMB maps, including the…

宇宙学与河外天体物理 · 物理学 2011-02-23 M. Landriau , E. P. S. Shellard

Analyses of recent cosmic microwave background (CMB) observations have provided increasing indications for the existence of large scale anisotropy in the universe. Given the far reaching consequences of such an anisotropy for our…

天体物理学 · 物理学 2009-09-29 A. Bernui , B. Mota , M. J. Reboucas , R. Tavakol

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…

天体物理学 · 物理学 2009-10-30 P. P. Avelino , R. R. Caldwell , C. J. A. P. Martins

We present a map and an angular power spectrum of the anisotropy of the cosmic microwave background (CMB) from the first flight of MAXIMA. MAXIMA is a balloon-borne experiment with an array of 16 bolometric photometers operated at 100 mK.…

We report on a measurement of the angular power spectrum of the anisotropy in the Cosmic Microwave Background. The anisotropy is measured in 23 different multipole bands from l=54 (~3 deg) to l=404 (~0.45 deg) and in 6 frequency bands from…

天体物理学 · 物理学 2009-10-28 C. B. Netterfield , M. J. Devlin , N. Jarosik , L. Page , E. J. Wollack

We present the first field-theoretic calculations of the contribution made by cosmic strings to the temperature power spectrum of the cosmic microwave background (CMB). Unlike previous work, in which strings were modeled as idealized…

天体物理学 · 物理学 2008-11-26 Neil Bevis , Mark Hindmarsh , Martin Kunz , Jon Urrestilla

Motivated by the morphological measures in assessing the geometrical and topological properties of a generic cosmological stochastic field, we propose an extension of the weighted morphological measures, specifically the $n$th conditional…

宇宙学与河外天体物理 · 物理学 2025-08-19 Adeela Afzal , M. Alakhras , M. H. Jalali Kanafi , S. M. S. Movahed

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…

宇宙学与河外天体物理 · 物理学 2015-03-17 Christophe Ringeval

We detect anisotropy in the cosmic microwave background (CMB) at degree angular scales and confirm a previous detection reported by Wollack et al. (1993). The root-mean-squared amplitude of the fluctuations is $44^{+13}_{-7} \mu$K. This may…

天体物理学 · 物理学 2008-11-26 C. B. Netterfield , N. Jarosik , L. Page , D. Wilkinson , E. Wollack

Sky temperature map of the cosmic microwave background (CMB) is one of the premier probes of cosmology. To minimize instrumentally induced systematic errors, CMB anisotropy experiments measure temperature differences across the sky using…

天体物理学 · 物理学 2008-06-30 Hao Liu , Ti-Pei Li

We study scalar mode perturbations (magnetosonic waves) induced by a helical stochastic cosmological magnetic field and derive analytically the corresponding cosmic microwave background (CMB) temperature and polarization anisotropy angular…

天体物理学 · 物理学 2008-11-26 Tina Kahniashvili , Bharat Ratra