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相关论文: Large-scale power in the CMB and new physics: an a…

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A recent application of the Kolmogorov-Smirnov test to the WMAP 7 year W-band maps claims evidence that the CMB is "weakly random", and that only 20% of the signal can be explained as a random Gaussian field. I here repeat this analysis,…

宇宙学与河外天体物理 · 物理学 2015-03-19 Sigurd Kirkevold Næss

The weak lensing power spectrum is a powerful tool to probe cosmological parameters. Additionally, lensing peak counts contain cosmological information beyond the power spectrum. Both of these statistics can be affected by the preferential…

宇宙学与河外天体物理 · 物理学 2014-03-07 Jia Liu , Zoltán Haiman , Lam Hui , Jan M. Kratochvil , Morgan May

The COBE detection of microwave anisotropies provides the best way of fixing the amplitude of cosmological fluctuations on the largest scales. We discuss the impact of this new, precise normalization and give fitting formulae for the…

天体物理学 · 物理学 2009-08-18 Martin White , Douglas Scott

We reconstruct the shape of the primordial power spectrum from the latest cosmic microwave background data, including the new results from the Wilkinson Microwave Anisotropy Probe (WMAP), and large scale structure data from the two degree…

天体物理学 · 物理学 2009-11-07 S. L. Bridle , A. M. Lewis , J. Weller , G. Efstathiou

The amplitudes of the quadrupole and octopole measured from the Wilkinson Microwave Anisotropy Probe (WMAP) appear to be lower than expected according to the concordance Lambda CDM cosmology. However, the pseudo-Cl estimator used by the…

天体物理学 · 物理学 2009-07-09 G. Efstathiou

Using a Gibbs sampling algorithm for joint CMB estimation and component separation, we compute the large-scale CMB and foreground posteriors of the 3-yr WMAP temperature data. Our parametric data model includes the cosmological CMB signal…

天体物理学 · 物理学 2010-11-11 H. K. Eriksen , C. Dickinson , J. B. Jewell , A. J. Banday , K. M. Gorski , C. R. Lawrence

The Cosmological Principle assumes a statistically isotropic Universe, but the Cosmic Microwave Background (CMB) exhibits some anomalous statistical features, such as the hemispherical power asymmetry, that challenge this core assumption.…

宇宙学与河外天体物理 · 物理学 2026-03-25 Javier Carrón Duque , Mikel Martin Barandiaran , Joseba Martínez-Arrizabalaga

The status of the standard cosmological model, also known as "LCDM" is described. With some simple assumptions, this model fits a wide range of data, with just six (or seven) free parameters. One should be skeptical about this claim, since…

宇宙学与河外天体物理 · 物理学 2018-04-05 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…

广义相对论与量子宇宙学 · 物理学 2021-09-21 Abhay Ashtekar , Brajesh Gupt , V. Sreenath

The angular power spectrum C_l is extracted from the 4 year COBE DMR data with a 20 degree galactic cut, using the narrowest window functions possible. The average power in eight multipole bands is also computed, and plotted together with a…

天体物理学 · 物理学 2009-10-28 Max Tegmark

A new method for estimating the power spectrum $C_l$ from cosmic microwave background (CMB) maps was recently presented by the author and applied to the 2 year COBE data. It was found that the spectral resolution $\Delta l$ for COBE could…

天体物理学 · 物理学 2016-08-30 Max Tegmark

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8 from the CMB, type Ia supernovae and from probes of large scale structure. We include the recent results from the CMB experiments BOOMERANG…

天体物理学 · 物理学 2007-05-23 S. L. Bridle

The measurements of the angular power spectrum of the Cosmic Microwave Background (CMB) anisotropy has proved crucial to the emergence of cosmology as a precision science in recent years. In this remarkable data rich period, the limitations…

天体物理学 · 物理学 2007-05-23 Sanjit Mitra , Anand S. Sengupta , Tarun Souradeep

Taking advantage of the smoothness of CMB Cl power spectra, we derive a simple and model-independent parameterization of their measurement. It allows to describe completely the spectrum, ie. provide an estimate of the value and the error…

天体物理学 · 物理学 2007-05-23 S. Plaszczynski , F. Couchot

Reconstruction of the linear power spectrum from observational data provides a way to compare cosmological models to a large amount of data, as Peacock & Dodds (1994, 1996) have shown. By applying the appropriate corrections to the…

天体物理学 · 物理学 2009-10-30 Clay Smith , Anatoly Klypin , Michael Gross , Joel Primack , Jon Holtzman

Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological models and parameters. However, precision can only be meaningful…

宇宙学与河外天体物理 · 物理学 2015-04-16 Santanu Das , Sanjit Mitra , Sonu Tabitha Paulson

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

天体物理学 · 物理学 2009-10-07 Max Tegmark

We investigate the ability to constrain oscillatory features in the primordial power spectrum using current and future cosmic microwave background observations. In particular, we study the observability of an oscillation arising from…

天体物理学 · 物理学 2011-05-12 Takemi Okamoto , Eugene A. Lim

In this paper, we propose & implement on WMAP 5-year data, a model independent approach of foreground power spectrum estimation for multifrequency observations of CMB experiments. Recently a model independent approach of CMB power spectrum…

宇宙学与河外天体物理 · 物理学 2009-08-03 Tuhin Ghosh , Rajib Saha , Pankaj Jain , Tarun Souradeep

It is widely believed that maximum likelihood estimators must be used to provide optimal estimates of power spectra. Since such estimators require require of order N_d^3 operations they are computationally prohibitive for N_d greater than a…

天体物理学 · 物理学 2008-11-26 G. Efstathiou