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相关论文: On the excess of power in high resolution CMB expe…

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The normalisation of the matter power spectrum, sigma_8, is an essential ingredient to predict the phenomenology of the low redshift universe. It has been measured using several methods, such as X-ray cluster counts, weak lensing and the…

天体物理学 · 物理学 2008-11-26 A. Amara , A. Refregier

We address whether possible scale-dependent deviations from gaussianity in the primordial density field that are consistent with the cosmic microwave background observations could explain the apparent excess of early cluster formation at…

天体物理学 · 物理学 2009-11-10 H. Mathis , J. M. Diego , Joseph Silk

In the context of the present and future Cosmic Microwave Background (CMB) experiments, going beyond the information provided by the power spectrum has become necessary in order to tightly constrain the cosmological model. The non-Gaussian…

天体物理学 · 物理学 2008-11-26 N. Aghanim , M. Kunz , P. G. Castro , O. Forni

We present final results on the angular power spectrum of total intensity anisotropies in the CMB from the CBI. Our analysis includes all primordial anisotropy data collected between January 2000 and April 2005, and benefits significantly…

We derive a general expression for the probability of observing deviations from statistical isotropy in the cosmic microwave background (CMB) if the primordial fluctuations are non-Gaussian and extend to superhorizon scales. The primary…

宇宙学与河外天体物理 · 物理学 2016-01-27 Saroj Adhikari , Sarah Shandera , Adrienne L. Erickcek

There is some observational evidence for earlier evolution of clusters of galaxies than predicted in the standard LambdaCDM model with a Gaussian primordial density fluctuation field, and a low value for the mass variance parameter sigma_8.…

天体物理学 · 物理学 2009-06-23 Yoel Rephaeli , Sharon Sadeh

Using large numbers of simulations of the microwave sky, incorporating the Cosmic Microwave Background (CMB) and the Sunyaev-Zel'dovich (SZ) effect due to clusters, we investigate the statistics of the power spectrum at microwave…

宇宙学与河外天体物理 · 物理学 2010-11-02 Michael W. Peel , Richard A. Battye , Scott T. Kay

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the…

宇宙学与河外天体物理 · 物理学 2020-04-07 Saroj Adhikari , Dragan Huterer

The decomposition of a signal on the sphere with the steerable wavelet constructed from the second Gaussian derivative gives access to the orientation, signed-intensity, and elongation of the signal's local features. In the present work,…

天体物理学 · 物理学 2009-11-13 Y. Wiaux , P. Vielva , R. B. Barreiro , E. Martinez-Gonzalez , P. Vandergheynst

A convincing detection of primordial non-Gaussianity in the cosmic background radiation (CMB) is essential to probe the physics of the early universe. Since a single statistical estimator can hardly be suitable to detect the various…

宇宙学与河外天体物理 · 物理学 2013-10-11 W. Cardona , A Bernui , M. J. Reboucas

Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, cluster abundance is sensitive to any non-Gaussianity of the primordial density field. It is therefore possible that non-Gaussian initial conditions might be…

天体物理学 · 物理学 2010-11-05 Emiliano Sefusatti , Chris Vale , Kenji Kadota , Joshua Frieman

We compare the latest results from CMB experiments at scales around $l_e \sim 150$ over different parts of the sky to test the hypothesis that they are drawn from a Gaussian distribution, as is usually assumed. Using both the diagonal and…

天体物理学 · 物理学 2009-10-30 E. Gaztanaga , P. Fosalba , E. Elizalde

We present predictions on the angular power spectrum of CMB fluctuations due to extragalactic point sources (EPS) by using a method for simulating realistic 2D distributions of clustered EPS. Both radio and far--IR selected source…

天体物理学 · 物理学 2009-11-10 J. González-Nuevo , L. Toffolatti , F. Argüeso

We study the power of several scalar quantities constructed on the sphere (presented in Monteserin et al. 2005) to detect non-Gaussianity on the temperature distribution of the cosmic microwave background (CMB). The test has been performed…

天体物理学 · 物理学 2009-11-11 C. Monteserin , R. B. Barreiro , E. Martinez-Gonzalez , J. L. Sanz

We discuss the nature of the possible high-l excess in the Cosmic Microwave Background (CMB) anisotropy power spectrum observed by the Cosmic Background Imager (CBI). We probe the angular structure of the excess in the CBI deep fields and…

Non-Gaussianity in the inflationary perturbations can couple observable scales to modes of much longer wavelength (even superhorizon), leaving as a signature a large-angle modulation of the observed cosmic microwave background (CMB) power…

宇宙学与河外天体物理 · 物理学 2013-05-30 Fabian Schmidt , Lam Hui

The evolution of the abundance of galaxy clusters is not a reliable measure of Omega if there are features on scales of a few Mpc in the primordial power spectrum. Conversely, if we know the cosmological model parameters from other…

天体物理学 · 物理学 2009-11-06 Alexander Knebe , Ranty Islam , Joseph Silk

We investigate the use of wavelet transforms in detecting and characterising non-Gaussian structure in maps of the cosmic microwave background (CMB). We apply the method to simulated maps of the Kaiser-Stebbins effect due to cosmic strings…

天体物理学 · 物理学 2009-10-31 MP Hobson , AW Jones , AN Lasenby

In this paper, we present results from the complete set of cosmic microwave background (CMB) radiation temperature anisotropy observations made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR) operating at 150 GHz. We include…

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