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Related papers: Dark Energy Cosmology with the Alternative Cosmic …

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We have reanalysed constraints on the equation of state parameter, w_Q = P/rho, of the dark energy, using several cosmological data sets and relaxing the usual constraint w_Q > -1. We find that combining Cosmic Microwave Background, large…

Astrophysics · Physics 2009-11-07 Steen Hannestad , Edvard Mortsell

The suggestion that we occupy a privileged position near the centre of a large, nonlinear, and nearly spherical void has recently attracted much attention as an alternative to dark energy. Putting aside the philosophical problems with this…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-11 Adam Moss , James P. Zibin , Douglas Scott

While the standard, six-parameter, spatially flat $\Lambda$CDM model has been highly successful, certain anomalies in the cosmic microwave background bring out a tension between this model and observations. The statistical significance of…

General Relativity and Quantum Cosmology · Physics 2021-09-21 Abhay Ashtekar , Brajesh Gupt , V. Sreenath

The large-angle (low-l) correlations of the Cosmic Microwave Background exhibit several statistically significant anomalies compared to the standard inflationary big-bang model, however no connection has hitherto been drawn between them.…

Astrophysics · Physics 2009-11-10 Dominik J. Schwarz , Glenn D. Starkman , Dragan Huterer , Craig J. Copi

Are geometrical summaries of the CMB and LSS sufficient for estimating cosmological parameters? And how does our choice of a dark energy model impact the current constraints on standard cosmological parameters? We address these questions in…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-17 Rahul Biswas , Benjamin D. Wandelt

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark…

Astrophysics · Physics 2016-01-13 J. Richard Bond , George Efstathiou , Max Tegmark

We describe how to compute estimates of the power spectrum C_l from Cosmic Microwave Background (CMB) maps that not only retain all the cosmological information, but also have uncorrelated error bars and well-behaved window functions. We…

Astrophysics · Physics 2007-05-23 Max Tegmark , Andrew Hamilton

We give a brief review of the known effects of a dynamical vacuum cosmological component, the dark energy, on the anisotropies of the cosmic microwave background (CMB). We distinguish between a "classic" class of observables, used so far to…

Astrophysics · Physics 2009-09-01 Carlo Baccigalupi , Viviana Acquaviva

Recent results regarding dark energy are mutually inconsistent under the $\Lambda$CDM cosmological model, hinting at the possibility of undiscovered physics. However, the currently accepted cosmological parameters come from a joint…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Charles L. Steinhardt , Preston Phillips , Radoslaw Wojtak

I describe briefly the Cosmic Microwave Background (hereafter CMB) physics which explains why high accuracy observations of its spatial structure are a unique observational tool both for the determination of the global cosmological…

Astrophysics · Physics 2007-05-23 Francois R. Bouchet

The dynamics of the Local Group (LG), especially the contribution of the Milky Way (MW) and Andromeda (M31) galaxies, is sensitive to the presence of dark energy. This work analyzes the evolution of the LG by considering it as a two-body…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-04 David Benisty

WMAP precision data enables accurate testing of cosmological models. We find that the emerging standard model of cosmology, a flat Lambda-dominated universe seeded by nearly scale-invariant adiabatic Gaussian fluctuations, fits the WMAP…

We present an approach to the problem of vacuum energy in cosmology, based on dynamical screening of Lambda on the horizon scale. We review first the physical basis of vacuum energy as a phenomenon connected with macroscopic boundary…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ignatios Antoniadis , Pawel O. Mazur , Emil Mottola

We cross-correlate the new 3 year Wilkinson Microwave Anistropy Probe (WMAP) cosmic microwave background (CMB) data with the NRAO VLA Sky Survey (NVSS) radio galaxy data, and find further evidence of late integrated Sachs-Wolfe (ISW) effect…

Astrophysics · Physics 2009-11-11 Davide Pietrobon , Amedeo Balbi , Domenico Marinucci

Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Cheng Cheng , Qing-Guo Huang

The residuals of the power spectra of WMAP and Planck's cosmic microwave background (CMB) anisotropies data are known to exhibit a few interesting anomalies at different scales with marginal statistical significance. Combining bottom-up and…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra

In this paper, we set the new limits on the equation of state parameter (EoS) of dark energy with the observations of cosmic microwave background radiation (CMB) from Planck satellite, the type Ia supernovae from Pan-STARRS and the baryon…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-15 Wei Zheng , Si-Yu Li , Hong Li , Jun-Qing Xia , Mingzhe Li , Tan Lu

We present a method for reducing cosmological data to constraints on the amplitudes of modes of the dark energy density as a function of redshift. The modes are chosen so that (1) one of them has constant density and (2) the others are…

Astrophysics · Physics 2007-05-23 Jason Dick , Lloyd Knox , Mike Chu

The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of…

Astrophysics · Physics 2009-11-10 A. Slosar , U. Seljak , A. Makarov

We present cosmological constraints from the combination of the full mission 9-year WMAP release and small-scale temperature data from the pre-Planck ACT and SPT generation of instruments. This is an update of the analysis presented in…

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