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相关论文: Signatures of Cosmic Strings on the Microwave Back…

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Using Monte Carlo simulations of perturbations induced by cosmic strings on the microwave background, we demonstrate the scale invariance of string fluctuation patterns. By comparing string-induced fluctuation patterns with gaussian random…

天体物理学 · 物理学 2009-10-28 Andrea M. Gilbert , 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…

高能物理 - 唯象学 · 物理学 2009-10-22 Leandros Perivolaropoulos

Using a simple analytic model based on seed superposition we obtain the spectrum of microwave background perturbations induced by cosmic strings on all angular scales larger than about 2 armin. We assume standard recombination in an…

天体物理学 · 物理学 2011-05-10 Leandros Perivolaropoulos

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

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…

天体物理学 · 物理学 2007-05-23 Leandros Perivolaropoulos

We use the analytical model recently introduced in Ref. \cite{lp92}, to investigate the statistics of temperature fluctuations on the cosmic microwave background (CMB), induced by topological defects. The cases of cosmic strings and…

高能物理 - 唯象学 · 物理学 2010-11-01 Leandros Perivolaropoulos

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…

天体物理学 · 物理学 2011-05-10 Mark Hindmarsh

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…

天体物理学 · 物理学 2011-05-10 L. Perivolaropoulos

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 compute analytically the small-scale temperature fluctuations of the cosmic microwave background from cosmic (super-)strings and study the dependence on the string intercommuting probability $P$. We develop an analytical model which…

In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known…

宇宙学与河外天体物理 · 物理学 2011-04-21 M. Sadegh Movahed , Shahram Khosravi

There exists various proposals to detect cosmic strings from Cosmic Microwave Background (CMB) or 21 cm temperature maps. Current proposals do not aim to find the location of strings on sky maps, all of these approaches can be thought of as…

宇宙学与河外天体物理 · 物理学 2017-09-01 Razvan Ciuca , Oscar F. Hernández

We introduce a new technique to detect the discrete temperature steps that cosmic strings might have left in the cosmic microwave background (CMB) anisotropy map. The technique provides a validity test on the pattern search of cosmic…

天体物理学 · 物理学 2009-11-11 E. Jeong , G. F. Smoot

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…

宇宙学与河外天体物理 · 物理学 2018-10-12 A. Vafaei Sadr , M. Farhang , S. M. S. Movahed , B. Bassett , M. Kunz

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…

宇宙学与河外天体物理 · 物理学 2013-08-15 M. Sadegh Movahed , B. Javanmardi , Ravi K. Sheth

We study future observational constraints on cosmic string parameters from various types of next-generation experiments: direct detection of gravitational waves (GWs), pulsar timing array, and the cosmic microwave background (CMB). We…

宇宙学与河外天体物理 · 物理学 2013-05-30 Sachiko Kuroyanagi , Koichi Miyamoto , Toyokazu Sekiguchi , Keitaro Takahashi , Joseph Silk

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…

天体物理学 · 物理学 2011-05-10 N. Simatos , L. Perivolaropoulos

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

Cosmic strings are predicted in many models beyond the Standard Model of particle physics. In models which admit strings, a network of strings will inevitably be formed in a phase transition in the early universe and will persist to the…

宇宙学与河外天体物理 · 物理学 2015-06-12 Robert H. Brandenberger

By using a simple analytical model based on counting random multiple impulses inflicted on photons by a network of cosmic strings we show how to construct the general q-point temperature correlation function of the Cosmic Microwave…

天体物理学 · 物理学 2011-05-10 Alejandro Gangui , Leandros Perivolaropoulos
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