نتایج جستجو برای: angular power spectrum aps
تعداد نتایج: 760576 فیلتر نتایج به سال:
The angular power spectrum of the Sunyaev–Zel’dovich (SZ) effect is a powerful probe of cosmology. It is easier to detect than individual clusters in the field, is insensitive to observational selection effects and does not require a calibration between cluster mass and flux, reducing the systematic errors which dominate the cluster-counting constraints. It receives a dominant contribution from...
We present preliminary results of an analysis into the effects of primordial voids on the cosmic microwave background (CMB). We show that an inflationary bubble model of void formation predicts excess power in the CMB angular power spectrum that peaks between 2000 < < 3000. Therefore, voids that exist on or close to the last scattering surface at the epoch of decoupling can contribute significa...
We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are robust. The data are modestly contaminated by diffuse Galactic foreground emission, but we show that a simple Galactic template model is sufficient to remove the ...
We present measurements of anisotropy in the Cosmic Microwave Background (CMB) from the first season of observations with the Degree Angular Scale Interferometer (DASI). The instrument was deployed at the South Pole in the austral summer 1999–2000, and made observations throughout the following austral winter. We present a measurement of the CMB angular power spectrum in the range 100 < l < 900...
We apply the hierarchical clustering model and non-linear perturbation theory to the cosmological density and temperature fields. This allows us to calculate the intergalactic gas pressure power spectrum, SZ anisotropy power spectrum, skewness and related statistics. Then we show the effect of the non-gravitational heating. Our model confirms recent simulations yielding mass weighted gas temper...
Weak lensing by large scale structure induces correlated ellipticities in the images of distant galaxies. The two-point correlation is determined by the matter power spectrum along the line of sight. We use the fully nonlinear evolution of the power spectrum to compute the predicted ellipticity correlation. We present results for different measures of the second moment for angular scales θ ≃ 1 ...
Abstract The conventional analytical channel models for multiple-input multiple-output (MIMO) wireless radio channels are array dependent. In this paper, we present several array independent MIMO channel models that inherit the essence of analytical models. The key idea is to decompose the physical scattering channel into two parts using the manifold decomposition technique: one is the wavefi...
Introduction: peak torque and peak joint power are two important variables in the performance of weightlifters. The purpose of this study was to investigate the effect of acute weight loss on the power and torque of the knee joint of elite weightlifters at different angular speeds of knee flexion and extension. Methods: The statistical sample of the research was selected according to the avail...
Abstract: The angular power spectrum of a stationary random field on the sphere is estimated from the needlet coefficients of a single realization, observed with increasingly fine resolution. The estimator we consider is similar to the one recently used in practice by (Faÿ et al. 2008) to estimate the power spectrum of the Cosmic Microwave Background. The consistency of the estimator, in the as...
We use the angular power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe. Within the class of Cold Dark Matter models, we find that the overall fractional energy density of the universe, Ω, is constrained to be 0.85 ≤ Ω ≤ 1.25 at the 68% confidence level. Combined with the COBE mea...
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