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Related papers: Cosmic Defects and CMB anisotropy

200 papers

We present a simple, yet accurate approximation for calculating the cosmic microwave background anisotropy power spectrum in adiabatic models. It consists of solving for the evolution of a two-fluid model until the epoch of recombination…

Astrophysics · Physics 2009-10-22 Uros Seljak

We present cosmological constraints on deviations of Newton's constant at large scales, analyzing latest cosmic microwave background (CMB) anisotropies and primordial abundances of light elements synthesized by big bang nucleosynthesis…

Astrophysics · Physics 2009-11-10 K. Umezu , K. Ichiki , M. Yahiro

We analyse CMB constraints on stable networks of cosmic strings and domain walls using for the first time full Planck 2018 data together with BICEP/Keck 2018 $B$-mode measurements. The defect-induced anisotropies are computed using the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-05 Luca Caloni , Ricardo Z. Ferreira , Lara Sousa , Clara Winckler

We compute the cosmic microwave background (CMB) anisotropy in a low-density, flat, cosmological constant, cold dark matter model which is normalized to the two-year COBE DMR sky map. Although conclusions regarding model viability must…

Astrophysics · Physics 2015-06-24 Bharat Ratra , Naoshi Sugiyama

We perform a detailed comparison of the Wilkinson Microwave Anisotropy Probe (WMAP) measurements of the cosmic microwave background (CMB) temperature and polarization anisotropy with the predictions of quintessence cosmological models of…

Astrophysics · Physics 2009-11-07 Robert R. Caldwell , Michael Doran

The primary results of most observations of cosmic microwave background (CMB) anisotropy are estimates of the angular power spectrum averaged through some broad band, called band-powers. These estimates are in turn what are used to produce…

Astrophysics · Physics 2016-08-25 Lloyd Knox

In this paper, we present results for large-angle CMB anisotropies generated from high resolution simulations of cosmic string networks in a range of flat FRW universes with a cosmological constant. Using an ensemble of all-sky maps, we…

Astrophysics · Physics 2008-11-26 M. Landriau , E. P. S. Shellard

Under the assumption that the concordance Lambda-cold dark matter (CDM) model is the correct model, we test the cosmic microwave background (CMB) anisotropy data for systematic effects by examining the band pass temperature residuals with…

Astrophysics · Physics 2009-11-10 Louise M. Griffiths , Charles H. Lineweaver

The information theory approach is suggested to the Cosmic Microwave Background (CMB) problem for negatively curved homogeneous and isotropic Universe. Namely, the Kolmogorov complexity of anisotropy of spots in CMB sky maps is proposed as…

Astrophysics · Physics 2009-10-31 V. G. Gurzadyan

Since the measurements of COBE/FIRAS in the mid-90's we know that the energy spectrum of the cosmic microwave background (CMB) is extremely close to that of a perfect blackbody at an average temperature T0~2.726K. However, a number of…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-11 Jens Chluba

Recent cosmic microwave background (CMB) results from BOOMERANG, MAXIMA, and DASI provide cosmological constraints on new physics that can be competitive with those derived from Big Bang Nucleosynthesis (BBN). In particular, both CMB and…

Astrophysics · Physics 2008-11-26 James P. Kneller , Robert J. Scherrer , Gary Steigman , Terry P. Walker

We present a general formalism for computing Cosmic Background Radiation (CBR) and density fluctuations in open models with stiff sources. We find analytic Green's functions for the linearized Einstein equations in the presence of stiff…

Astrophysics · Physics 2010-11-01 Ue-Li Pen , David N. Spergel

We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-10 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

Anomalies in the cosmic microwave background (CMB) refer to features that have been observed, mostly at large angular scales, and which show some tension with the statistical predictions of the standard $\Lambda$CDM model. In this work, we…

General Relativity and Quantum Cosmology · Physics 2021-05-28 Ivan Agullo , Dimitrios Kranas , V. Sreenath

Ever refined cosmological measurements have established the $\Lambda$CDM concordance model, with the key cosmological parameters being determined to percent-level precision today. This allows us to make explicit predictions for the spectral…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-23 Jens Chluba

This is a very exciting time for the CMB field. It is widely recognized that precision measurements of the CMB can provide a definitive test of cosmological models and determine their parameters accurately. At present observations give us…

Astrophysics · Physics 2007-05-23 George F. Smoot

Measurements of cosmic microwave background (CMB) anisotropies by interferometers offer several advantages over single-dish observations. The formalism for analyzing interferometer CMB data is well developed in the flat-sky approximation,…

Astrophysics · Physics 2008-11-26 Emory F. Bunn , Martin White

The measurements of CMB anisotropy have opened up a window for probing the global topology of the universe on length scales comparable to and beyond the Hubble radius. For compact topologies, the two main effects on the CMB are: (1) the…

Astrophysics · Physics 2011-04-15 J. Richard Bond , Dmitri Pogosyan , Tarun Souradeep

We examine the degree to which observations of large-scale cosmic microwave background (CMB) polarization can shed light on the puzzling large-scale power modulation in maps of CMB anisotropy. We consider a phenomenological model in which…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Emory F. Bunn , Qingyang Xue , Haoxuan Zheng

New precision Cosmic Microwave Background Radiation (CMBR) anisotropy data are beginning to constrain physics beyond the standard model, for example in the form of additional light particle species. These constraints are complementary to…

Astrophysics · Physics 2009-11-06 Steen Hannestad