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Related papers: Texture-Induced Microwave Background Anisotropies

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The cosmic microwave anisotropies in a scenario of large scale structure formation with cold dark matter and texture are discussed and compared with recent observational results of the COBE satellite. A couple of important statistical…

Astrophysics · Physics 2008-11-26 R. Durrer , A. Howard , Z. -H. Zhou

We study microwave background anisotropies induced by scaling seed perturbations in a universe dominated by cold dark matter. Using a gauge invariant linear perturbation analysis, we solve the perturbation equations on super-horizon scales,…

Astrophysics · Physics 2009-10-30 Ruth Durrer , Mairi Sakellariadou

We present an analysis of CMB anisotropies induced by global scalar fields in the large N limit. In this limit, the CMB anisotropy spectrum can be determined without cumbersome 3D simulations. We determine the source functions and their…

Astrophysics · Physics 2016-08-30 Martin Kunz , Ruth Durrer

Using an analytical model for the Cosmic Microwave Background anisotropies produced by textures, we compute the resulting collapsed three--point correlation function and the {\it rms} expected value due to the cosmic variance. We apply our…

Astrophysics · Physics 2009-10-28 Alejandro Gangui , Silvia Mollerach

It is likely that the observed large-angular-scale anisotropies in the microwave background radiation are induced by the cosmological perturbations of quantum-mechanical origin. Such perturbations are now placed in squeezed vacuum quantum…

General Relativity and Quantum Cosmology · Physics 2009-10-28 L. P. Grishchuk

The COBE satellite's maps of the cosmic microwave background (CMB) anisotropy do not have the resolution to discriminate between theories of cosmic structure formation based on inflation, and those based on field ordering following a…

High Energy Physics - Phenomenology · Physics 2009-09-25 David Coulson , Ue-Li Pen , Neil Turok

The power spectrum of temperature anisotropies induced by hot intracluster gas on the cosmic background radiation is calculated. For low multipoles it remains constant while at multipoles above $l>2000$ it is exponentially damped. The shape…

Astrophysics · Physics 2009-10-31 F. Atrio Barandela , J. P. Muecket

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 compute cosmic microwave background angular power spectra for scaling seed models of structure formation. A generic parameterization of the energy momentum tensor of the seeds is employed. We concentrate on two regions of parameter space…

Astrophysics · Physics 2008-11-26 R. Durrer , M. Kunz , C. Lineweaver , M. Sakellariadou

The theoretical basis for the prediction of anisotropies in the cosmic microwave background is very well developed. Very low amplitude density and temperature perturbations produce small gravitational effects, leading to an anisotropy that…

Astrophysics · Physics 2007-05-23 E. L. Wright

The genuine quantum gravity effects can already be around us. It is likely that the observed large-angular-scale anisotropies in the microwave background radiation are induced by cosmological perturbations of quantum-mechanical origin. Such…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. P. Grishchuk

The cosmic microwave background anisotropies produced by active seeds, such as topological defects, have been computed recently for a variety of models by a number of authors. In this paper we show how the generic features of the…

General Relativity and Quantum Cosmology · Physics 2017-10-04 Alain Riazuelo , Nathalie Deruelle

This article describes the computation of cosmic microwave background anisotropies in a universe with multi-connected spatial sections and focuses on the implementation of the topology in standard CMB computer codes. The key ingredient is…

Astrophysics · Physics 2009-11-07 Alain Riazuelo , Jean-Philippe Uzan , Roland Lehoucq , Jeffrey Weeks

A new method is proposed for modelling spherically symmetric inhomogeneities in the Universe. The inhomogeneities have finite size and are compensated, so they do not exert any measurable gravitational force beyond their boundary. The…

Astrophysics · Physics 2009-10-31 A. N. Lasenby , C. J. L. Doran , M. P. Hobson , Y. Dabrowski , A. D. Challinor

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

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

Previous estimates of the microwave background anisotropies produced by freely falling spherical clusters are discussed. These estimates are based on the Swiss-Cheese and Tolman-Bondi models. It is proved that these models give only upper…

Astrophysics · Physics 2015-06-24 V. Quilis , J. M. Ibanez , D. Saez

In this paper we develop the theory of clusterization of peaks in a Gaussian random field. We have obtained new mathematical results from this theory and the theory of percolation and have proposed a topological method of analysis of sky…

Astrophysics · Physics 2009-10-28 D. I. Novikov , H. E. Jorgensen

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the absence of significant acoustic peaks and little power on large…

Astrophysics · Physics 2009-10-31 Ruth Durrer , Martin Kunz , Alessandro Melchiorri

Fluctuations in the temperature of the cosmic microwave background have now been detected over a wide range of angular scales, and a consistent picture seems to be emerging. This article describes some of the implications for cosmology.…

Astrophysics · Physics 2009-10-28 Douglas Scott , Joe Silk , Martin White
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