Fast CMB Power Spectrum Estimation of Temperature and Polarisation with Gabor Transforms (2002)
Hansen, Frode K., Gorski, Krzysztof M.
We extend the analysis of Gabor transforms on a Cosmic Microwave Background (CMB) temperature map (Hansen, Gorski and Hivon 2002) to polarisation. We study the temperature and polarisation power...
Gabor Transforms on the Sphere with Applications to CMB Power Spectrum Estimation (2002)
Hansen, Frode K., Gorski, Krzysztof M., Hivon, Eric
The Fourier transform of a dataset apodised with a window function is known as the Gabor transform. In this paper we extend the Gabor transform formalism to the sphere with the intention of applying...
Measurement of the cosmic microwave background bispectrum on the COBE DMR sky maps (2001)
Komatsu, Eiichiro, Wandelt, Benjamin D., Spergel, David N., Banday, Anthony J., Gorski, Krzysztof M.
We measure the angular bispectrum of the cosmic microwave background (CMB) radiation anisotropy from the COBE Differential Microwave Radiometer (DMR) four-year sky maps. The angular bispectrum is the...
Fast Convolution on the Sphere (2000)
Wandelt, Benjamin D., Gorski, Krzysztof M.
We propose fast, exact and efficient algorithms for the convolution of two arbitrary functions on the sphere which speed up computations by a factor \order{\sqrt{N}} compared to present methods where...
Wandelt, Benjamin D., Hivon, Eric, Gorski, Krzysztof M.
As the era of high precision cosmology approaches, the empirically determined power spectrum of the microwave background anisotropy $C_l$ will provide a crucial test for cosmological theories. We...
Multiparameter estimation with the Pseudo-C_l method (2000)
Wandelt, Benjamin D., Gorski, Krzysztof M., Hivon, Eric
We apply the Pseudo-C_l formalism to obtain an unbiased, approximate method for efficient simultaneous estimation of several cosmological parameters from large, almost full-sky cosmic microwave...
Gorski, Krzysztof M., Wandelt, Benjamin D., Hansen, Frode K., Hivon, Eric, Banday, Anthony J.
HEALPix is a Hierarchical, Equal Area, and iso-Latitude Pixelisation of the sphere designed to support efficiently - local operations on the pixel set, - a hierarchical tree structure for...
Rocha, Graca, Stompor, Radoslaw, Ganga, Ken, Ratra, Bharat, Platt, Stephen R., Sugiyama, Naoshi, ...
We use Python I, II, and III cosmic microwave background anisotropy data to constrain cosmogonies. We account for the Python beamwidth and calibration uncertainties. We consider open and...
Where is the COBE maps' non-Gaussianity? (1999)
Magueijo, Joao, Ferreira, Pedro G., Gorski, Krzysztof M.
We review our recent claim that there is evidence of non-Gaussianity in the 4 Year COBE DMR data. We present some new results concerning the effect of the galactic cut upon the non-Gaussian signal....
Ratra, Bharat, Stompor, Radoslaw, Ganga, Ken, Rocha, Graca, Sugiyama, Naoshi, Gorski, Krzysztof M.
We use combinations of ten small-scale cosmic microwave background anisotropy data sets from the UCSB South Pole 1994, ARGO, MAX 4 and 5, White Dish and SuZIE experiments to constrain cosmogonies. We...
CMB anisotropy power spectrum statistics (1998)
Wandelt, Benjamin D., Hivon, Eric, Gorski, Krzysztof M.
Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly...
Cosmic microwave background anisotropy power spectrum statistics for high precision cosmology (1998)
Wandelt, Benjamin D., Hivon, Eric, Gorski, Krzysztof M.
As the era of high precision cosmology approaches, the empirically determined power spectrum of the microwave background anisotropy, $C_l$, will provide a crucial test for cosmological theories. We...
ARGO CMB Anisotropy Measurement Constraints on Open and Flat-Lambda CDM Cosmogonies (1998)
Ratra, Bharat, Ganga, Ken, Stompor, Radoslaw, Sugiyama, Naoshi, De Bernardis, Paolo, Gorski, Krzysztof M.
We use data from the ARGO cosmic microwave background (CMB) anisotropy experiment to constrain cosmogonies. We account for the ARGO beamwidth and calibration uncertainties, and marginalize over the...
Schmalzing, Jens, Gorski, Krzysztof M.
We present a novel approach to quantifying the morphology of Cosmic Microwave Background (CMB) anisotropy maps. As morphological descriptors, we use shape parameters known as Minkowski functionals....
Direct Imaging of the CMB from Space (1996)
Janssen, Michael A., Scott, Douglas, White, Martin, Seiffert, Michael D., Lawrence, Charles R., Gorski, Krzysztof M., ...
Fundamental information about the Universe is encoded in anisotropies of the Cosmic Microwave Background (CMB) radiation. To make full use of this information, an experiment must image the entire sky...
CMB Anisotropy in COBE-DMR-Normalized Open CDM Cosmogony (1995)
Ratra, Bharat, Banday, Anthony J., Gorski, Krzysztof M., Sugiyama, Naoshi
We compute the CMB anisotropy in an open inflation CDM model which is normalized to the two-year DMR sky map. Presently available CMB data is consistent with $\Omega_0 \sim 0.3 - 0.4$, but does not...
COBE-DMR-normalisation for Cold and Mixed Dark Matter Models Inflationary Cosmogony (1995)
Gorski, Krzysztof M., Stompor, Radoslaw, Banday, Anthony J.
The two-year COBE-DMR 53 and 90 GHz sky maps in both ecliptic and galactic coordinates, are used to determine the normalisation of inflationary, flat, dark matter dominated universe models. The...
COBE-DMR-normalised Open Inflation, CDM Cosmogony (1995)
Gorski, Krzysztof M., Ratra, Bharat, Sugiyama, Naoshi, Banday, Anthony J.
Fourier analysis on a cut sky of the two-year COBE DMR 53 and 90 GHz sky maps (in galactic coordinates) is used to determine the normalisation of an open inflation model based on the cold dark matter...
COBE-DMR-normalisation for Cosmological Constant Dominated Cold Dark Matter Models (1995)
Stompor, Radoslaw, Gorski, Krzysztof M., Banday, Anthony J.
The two-year COBE-DMR 53 and 90 GHz sky maps are used to determine the normalization of inflationary, cosmological constant dominated, cold dark matter models. Although the COBE-DMR data prefer a...
On Determining the Spectrum of Primordial Inhomogeneity from the COBE DMR Sky Maps: I. Method (1994)
The natural approach to a spectral analysis of data distributed on the sky employs spherical harmonic decomposition. A common problem encountered in practical astronomy is the lack of full sky...