We present improved results on the measurement of the angular power spectrum of the Cosmic Microwave Background (CMB) temperature anisotropies using the data from the last A flight. This refined analysis is obtained by using the 6 most sensitive photometric pixels in the CMB bands centered at 143 and 217 GHz and 20% of the sky, mostly clear of foregrounds. Using two different cross-corre...

Observational evidence shows that gravitational lensing induces an angular correlation between the distribution of galaxies and much more distant QSO’s. We use weak gravitational lensing theory to calculate this angular correlation, updating previous calculations and presenting new results exploring the dependence of the correlation on the large-scale structure. We study the dependence of the p...

We have analysed the angular power spectra of the Parkes radio continuum and polarisation survey of the Southern galactic plane at 2.4 GHz. We have found that in the multipole range l = 40–250 the angular power spectrum of the polarised intensity is well described by a power-law spectrum with fitted spectral index αL = 2.37 ± 0.21. In the same multipole range the angular power spectra of the E ...

We briefly review recent developments in black hole accretion disk theory, placing new emphasis on the vital role played by magnetohydrodynamic (MHD) stresses in transporting angular momentum. The apparent universality of accretion-related outflow phenomena is a strong indicator that vertical transport of angular momentum by large-scale MHD torques is important and may even dominate radial tran...

Archeops is a balloon-borne experiment designed to measure the temperature fluctuations of the CMB on a large region of the sky (≃ 30%) with a high angular resolution (10 arcminutes) and a high sensitivity (60µK per pixel). Archeops will perform a measurement of the CMB anisotropies power spectrum from large angular scales (ℓ ≃ 30) to small angular scales (ℓ ≃ 800). Archeops flew for the first ...

We review recent work aimed at showing how global topolog-ical defects influence the shape of the angular power spectrum of the cosmic microwave background radiation on small scales. While Sachs–Wolfe fluctuations give the dominant contribution on angular scales larger than about a few degrees, on intermediate scales, 0.1 • < ∼ θ < ∼ 2 • , the main rôle is played by coherent oscillations in the...

We briefly review recent developments in black hole accretion disk theory, emphasizing the vital role played by magnetohydrodynamic (MHD) stresses in transporting angular momentum. The apparent universality of accretion-related outflow phenomena is a strong indicator that large-scale MHD torques facilitate vertical transport of angular momentum. This leads to an enhanced overall rate of angular...

PURPOSE Computed tomography (CT) performance as well as dose and image quality is directly affected by the x-ray spectrum. However, the current assessment approaches of the CT x-ray spectrum require costly measurement equipment and complicated operational procedures, and are often limited to the spectrum corresponding to the center of rotation. In order to address these limitations, the authors...

We apply the Gabor transform methodology proposed in (Hansen et al. 2002, 2003) to the WMAP data in order to test the statistical properties of the CMB fluctuation field and specifically to evaluate the fundamental assumption of cosmological isotropy. In particular, we apply the transform with several apodisation scales, thus allowing the determination of the positional dependence of the angula...

The majority of gamma-ray emission from Galactic dark matter annihilation is likely to be detected as a contribution to the diffuse gamma-ray background. I show that dark matter substructure in the halo of the Galaxy induces characteristic anisotropies in the diffuse background that could be used to determine the small-scale dark matter distribution. I calculate the angular power spectrum of th...