English
Related papers

Related papers: Cosmic Strings as the Source of Small-Scale Microw…

200 papers

During the last years it has become clear that global O(N) defects and U(1) cosmic strings do not lead to the pronounced first acoustic peak in the power spectrum of anisotropies of the cosmic microwave background which has recently been…

Astrophysics · Physics 2008-11-26 R. Durrer , M. Kunz , A. Melchiorri

Pulsar timing arrays are one of the powerful tools to test the existence of cosmic strings through searching for the gravitational wave background. The amplitude of the background connects to information on cosmic strings such as the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-03 Sachiko Kuroyanagi , Keitaro Takahashi , Naoyuki Yonemaru , Hiroki Kumamoto

We present a new probe of purely gravitationally coupled sectors with large anisotropies. These anisotropies are damped via gravitational interactions with the baryon-photon fluid, which is heated up in the process. The injected heat causes…

High Energy Physics - Phenomenology · Physics 2023-02-16 Nicklas Ramberg , Wolfram Ratzinger , Pedro Schwaller

We have investigated the cosmic microwave background (CMB) anisotropy in closed multiply connected universes (flat and hyperbolic) with low matter density. We show that the COBE constraints on these low matter density models with…

Astrophysics · Physics 2016-08-30 Kaiki Taro Inoue

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…

Astrophysics · Physics 2011-04-15 Ruth Durrer

Cosmic strings are linear concentrations of energy that form whenever phase transitions in the early universe break axial symmetries as originally shown by Kibble. They are the result of frustrated order in the quantum fields responsible…

Astrophysics · Physics 2008-11-11 A. Achucarro , C. J. A. P. Martins

We present a significant improvement over our previous calculations of the cosmic string contribution to cosmic microwave background (CMB) power spectra, with particular focus on sub-WMAP angular scales. These smaller scales are relevant…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Neil Bevis , Mark Hindmarsh , Martin Kunz , Jon Urrestilla

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…

Astrophysics · Physics 2008-11-26 C. B. Netterfield , N. Jarosik , L. Page , D. Wilkinson , E. Wollack

A theory of quantum-mechanical generation of cosmological perturbations is considered. The conclusion of this study is that if the large-angular-scale anisotropy in the cosmic microwave background radiation is caused by the long-wavelength…

General Relativity and Quantum Cosmology · Physics 2009-09-25 L. P. Grishchuk

We use wavelet and curvelet transforms to extract signals of cosmic strings from cosmic microwave background (CMB) temperature anisotropy maps, and to study the limits on the cosmic string tension which various ongoing CMB temperature…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Lukas Hergt , Adam Amara , Robert Brandenberger , Tomasz Kacprzak , Alexandre Refregier

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…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Rebecca J. Danos , Robert H. Brandenberger

We study the evolution of curvature perturbations and the cosmic microwave background (CMB) power spectrum in the presence of an hypothesized extra anisotropic stress which might arise, for example, from the dark radiation term in…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Kazuhiko Kojima , Toshitaka Kajino , Grant J. Mathews

We perform a multiparameter likelihood analysis to compare measurements of the cosmic microwave background (CMB) power spectra with predictions from models involving cosmic strings. Adding strings to the standard case of a primordial…

Astrophysics · Physics 2008-11-26 Neil Bevis , Mark Hindmarsh , Martin Kunz , Jon Urrestilla

We investigate the contribution made by small loops from a cosmic string network as seeds for large-scale structure formation. We show that cosmic string loops are highly correlated with the long-string network on large scales and therefore…

Astrophysics · Physics 2008-11-26 P. P. Avelino , E. P. S. Shellard , J. H. P. Wu , B. Allen

An inhomogeneous cosmological magnetic field creates vortical perturbations that survive Silk damping on much smaller scales than compressional modes. This ensures that there is no sharp cut-off in anisotropy on arc-minute scales. As we had…

Astrophysics · Physics 2009-11-07 Kandaswamy Subramanian , John D. Barrow

We report a search for signatures of cosmic strings in the the Cosmic Microwave Background data from the Wilkinson Microwave Anisotropy Probe. We used a digital filter designed to search for individual cosmic strings and found no evidence…

Astrophysics · Physics 2007-05-23 Amy S. Lo , Edward L. Wright

A conventional explanation of the dipole anisotropy of the cosmic microwave background (CMB) radiation is in terms of the Doppler effect: our galaxy is moving with respect to CMB frame with $ \sim 600 ~ km ~ s^{-1} $. However, as the deep…

Astrophysics · Physics 2007-05-23 M. Jaroszynski , B. Paczynski

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…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-22 Christophe Ringeval , Francois R. Bouchet

At its very beginning, the universe is believed to have grown exponentially in size via the mechanism of inflation. The almost scale-invariant density perturbation spectrum predicted by inflation is strongly supported by cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 David F. Chernoff , S. -H. Henry Tye

We study the cosmic microwave background temperature and polarisation spectra sourced by multi-tension cosmic superstring networks. First we obtain solutions for the characteristic length scales and velocities associated with the evolution…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Alkistis Pourtsidou , Anastasios Avgoustidis , Edmund J. Copeland , Levon Pogosian , Daniele A. Steer
‹ Prev 1 3 4 5 6 7 10 Next ›