中文
相关论文

相关论文: Exact likelihood evaluations and foreground margin…

200 篇论文

The compression of multi-frequency cosmic microwave background (CMB) power spectrum measurements into a series of foreground-marginalised CMB-only band powers allows for the construction of faster and more easily interpretable 'lite'…

宇宙学与河外天体物理 · 物理学 2025-02-19 L. Balkenhol

The estimation of the covariance matrix is an initial step in many multivariate statistical methods such as principal components analysis and factor analysis, but in many practical applications the dimensionality of the sample space is…

统计方法学 · 统计学 2012-06-12 Søren Feodor Nielsen , Jon Sporring

Following this astro-ph communication, we release a set of 10,000 WMAP ILC simulations, produced as described by Eriksen et al. (2004). We strongly encourage that an analysis of these simulations accompanies any scientific analysis of the…

天体物理学 · 物理学 2007-05-23 H. K. Eriksen , A. J. Banday , K. M. Gorski , P. B. Lilje

We have investigated the odd-parity preference of the WMAP 7 year power spectrum. Comparison with simulation shows the odd-parity preference of WMAP data (2<= l <=22) is anomalous at 4-in-1000 level. We have investigated its origins, and…

宇宙学与河外天体物理 · 物理学 2014-11-20 Jaiseung Kim , Pavel Naselsky

We analyze first-year data of WMAP to determine the significance of asymmetry in summed power between arbitrarily defined opposite hemispheres, using maps that we create ourselves with software developed independently of the WMAP team. We…

天体物理学 · 物理学 2010-11-11 P. E. Freeman , C. R. Genovese , C. J. Miller , R. C. Nichol , L. Wasserman

We show that the first year results of the Wilkinson Microwave Anisotropy Probe (WMAP) constrain very efficiently the energy density in relativistic particles in the universe. We derive new bounds on additional relativistic degrees of…

天体物理学 · 物理学 2016-08-30 Patrick Crotty , Julien Lesgourgues , Sergio Pastor

Microwave background temperature and polarization observations are a powerful way to constrain cosmological parameters if the likelihood function can be calculated accurately. The temperature and polarization fields are correlated, partial…

天体物理学 · 物理学 2012-04-25 Samira Hamimeche , Antony Lewis

The Wilkinson Microwave Anisotropy Probe (WMAP) has measured lower amplitudes for the temperature quadrupole and octopole anisotropies than expected in the best fitting (concordance) Lambda-dominated cold dark matter cosmology. Some authors…

天体物理学 · 物理学 2009-11-10 G. Efstathiou

We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…

We use the results from the Wilkinson Microwave Anisotropy Probe (WMAP) for the locations of peaks and troughs of the Cosmic Microwave Background (CMB) power spectrum, together with constraints from large-scale structure, to study a…

天体物理学 · 物理学 2016-11-09 T. Barreiro , M. C. Bento , N. M . C. Santos , A. A. Sen

We perform an independent foreground analysis of the WMAP maps to produce a cleaned CMB map (available online) useful for cross-correlation with, e.g., galaxy and X-ray maps. We use a variant of the Tegmark & Efstathiou (1996) technique…

天体物理学 · 物理学 2009-10-07 Max Tegmark , Angelica de Oliveira-Costa , Andrew Hamilton

We cross-correlate WMAP and ROSAT diffuse X-ray background maps and look for common features in both data sets. We use the power spectrum of the product maps and the cross-power spectrum to highlight a possible correlation. The power…

天体物理学 · 物理学 2009-11-07 J. M. Diego , J. Silk , W. Sliwa

We propose counting peaks in weak lensing (WL) maps, as a function of their height, to probe models of dark energy and to constrain cosmological parameters. Because peaks can be identified in two-dimensional WL maps directly, they can…

宇宙学与河外天体物理 · 物理学 2010-04-06 Jan M. Kratochvil , Zoltán Haiman , Morgan May

This paper focuses on cosmological constraints derived from analysis of WMAP data alone. A simple LCDM cosmological model fits the five-year WMAP temperature and polarization data. The basic parameters of the model are consistent with the…

The recent three-year WMAP data have confirmed the anomaly concerning the low quadrupole amplitude compared to the best-fit \Lambda CDM prediction. We show that, allowing the large-scale spatial geometry of our universe to be…

天体物理学 · 物理学 2008-12-18 L. Campanelli , P. Cea , L. Tedesco

The B-mode polarization of the cosmic microwave background (CMB) provides a unique window into tensor perturbations from inflationary gravitational waves. Survey effects complicate the estimation and description of the power spectrum on the…

宇宙学与河外天体物理 · 物理学 2016-09-28 Eric R. Switzer , Duncan J. Watts

Polarization is the next frontier of CMB analysis, but its signal is dominated over much of the sky by foregrounds which must be carefully removed. To determine the efficacy of this cleaning it is necessary to have sensitive tests for…

天体物理学 · 物理学 2007-09-06 Duncan Hanson , Douglas Scott , Emory F. Bunn

Improved polarization measurements at frequencies below 70 GHz with degree-level angular resolution are crucial for advancing our understanding of the Galactic synchrotron radiation and the potential polarized anomalous microwave emission…

This paper provides full sky maps of foreground emission in all WMAP channels, with very low residual contamination from the Cosmic Microwave Background (CMB) anisotropies and controlled level of instrumental noise. Foreground maps are…

宇宙学与河外天体物理 · 物理学 2013-09-25 Tuhin Ghosh , Jacques Delabrouille , Mathieu Remazeilles , Jean-Francois Cardoso , Tarun Souradeep

We have investigated non-Gaussianity of our early Universe by comparing the parity asymmetry of the WMAP power spectrum with simulations. We find that odd-parity preference of the WMAP data (2<= l <=18) is anomalous at 4-in-1000 level. We…

宇宙学与河外天体物理 · 物理学 2010-05-25 Jaiseung Kim , Pavel Naselsky