The APM Galaxy Survey maps the angular positions of more than one million galaxies to bJ = 20, covering a volume comparable to the forthcoming Sloan Digital Sky Survey. A numerical algorithm has been developed to estimate the power spectrum in three dimensions, using the angular clustering and a model for the redshift distribution of APM Galaxies. The power spectrum obtained is free from distor...

We have developed a fast method for predicting the angular power spectrum, Cl, of the cosmic microwave background given cosmological parameters and a primordial power spectrum of perturbations. After pre–computing the radiation temperature and gravitational potential transfer functions over a small sub–space of the total model parameter space, the rest of the model space (six or more cosmologic...

Here we present and analyze an optical spectrum analyzer at the nanometer scale that is able to distribute different frequency contents of the radiation of an optical dipole source into different directions in the space. The spectrum analyzer is composed of arrays of optical Yagi-Uda nanoantennas, forming relatively narrow radiation patterns operating at different frequencies. The optical Yagi-...

We describe the angular power spectrum of resolved sources at 3.6 μm (L-band) in Spitzer imaging data of the GOODS HDF-N, the GOODS CDF-S, and the NDWFS Boötes field in several source magnitude bins. We also measure angular power spectra of resolved sources in the Boötes field at KS and J-bands using ground-based IR imaging data. In the three bands, J, KS, and L, we detect the clustering of gal...

We calculate the angular power spectrum of the galactic synchrotron radiation induced by the small scale fluctuations of the magnetic field and the cosmic ray electron density. Using the observed interstellar magnetic field spectrum, which is consistent with the Komolgorov turbulence model at the relevant scales, we find that Cl ∝ l−3.7. We estimate the cosmic ray electron density fluctuation s...

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 we made observations throughout the following austral winter. We present a measurement of the CMB angular power spectrum in the range 100 < l < ...

We observed in §2.1 that if the propagation distance z is small, then the propagation problem may be accurately and efficiently solved in the Fourier domain. This is not a new observation—see, e.g., [16, 14]—so our objective here is simply to demonstrate how this propagation method (the so-called angular spectrum method) can be implemented using the quadratures from Theorem 2 to ensure any user...

Under the standard model for recombination of the primeval plasma, and the cold dark matter model for structure formation, recent measurements of the first peak in the angular power spectrum of the cosmic microwave background temperature indicate the spatial geometry of the universe is nearly flat. If sources of Ly α resonance radiation, such as stars or active galactic nuclei, were present at ...

We report on a new class of exact solutions of the scalar Helmholtz equation obtained by carefully engineering the form of the angular spectrum of a Bessel beam. We consider in particular the case in which the angular spectrum of such generalized beams has, in the paraxial zone, the same radial structure as Laguerre-Gaussian beams. We investigate the form of these new beams as well as their pec...

We study some spectral features of the one–particle electron Hamiltonian obtained by separating the Dirac equation in a Kerr–Newman black hole background. We find that the essential spectrum includes the whole real line. As a consequence, there is no gap in the spectrum and discrete eigenvalues are not allowed for any value of the black hole charge Q and angular momentum J . Our spectral analys...