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The combined analysis of the cosmic microwave background on large scales and Lyman-alpha forest on small scales provides a sufficiently long lever arm to obtain strong constraints on the slope and curvature of the power spectrum of…

Astrophysics · Physics 2009-11-10 Matteo Viel , Jochen Weller , Martin Haehnelt

We propose a formalism for estimating the skewness and angular power spectrum of a general Cosmic Microwave Background data set. We use the Edgeworth Expansion to define a non-Gaussian likelihood function that takes into account the…

Astrophysics · Physics 2010-04-30 C. R. Contaldi , P. G. Ferreira , J. Magueijo , K. M. Gorski

There is enormous potential to advance cosmology from statistical characterizations of cosmic microwave background sky maps. The angular power spectrum of the microwave anisotropy is a particularly important statistic. Existing algorithms…

Astrophysics · Physics 2009-10-30 Siang Peng Oh , David N. Spergel , Gary Hinshaw

In this work we explore the possibility of variations in the primordial scalar power spectrum around the power-law shape, as predicted by single-field slow-roll inflationary scenarios. We search for the trace of these fluctuations in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Marzieh Farhang , Muhammad Sadegh Esmaeilian

The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of…

Astrophysics · Physics 2009-11-10 A. Slosar , U. Seljak , A. Makarov

The spectral variation of the cosmic microwave background (CMB) as observed by WMAP was tested using foreground reduced WMAP5 data, by producing subtraction maps at the 1$^\circ$ angular resolution between the two cosmological bands of V…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Bi-Zhu Jiang , Richard Lieu , Shuang-Nan Zhang , Bart Wakker

A new technique of Fourier analysis on a cut sky (Gorski, 1994) has been applied to the two year COBE DMR sky maps. The Bayesian power spectrum estimation results are consistent with the Harrison-Zel'dovich n=1 model. The maximum likelihood…

Astrophysics · Physics 2009-06-16 K. M. Gorski , G. Hinshaw , A. J. Banday , C. L. Bennett , E. L. Wright , A. Kogut , G. F. Smoot , P. Lubin

We use recent results from the Wilkinson Microwave Anisotropy Probe (WMAP) for the locations of peaks and troughs of the Cosmic Microwave Background (CMB) power spectrum, together with constraints from large-scale structure, to study a…

Astrophysics · Physics 2009-11-07 T. Barreiro , M. C. Bento , N. M. C. Santos , A. A. Sen

(Abridged) A simple six-parameter LCDM model provides a successful fit to WMAP data, both when the data are analyzed alone and in combination with other cosmological data. Even so, it is appropriate to search for any hints of deviations…

We use the localized principle component analysis to detect deviations from scale invariance of the primordial power spectrum of curvature perturbations. With the technique we make uncorrelated estimates of the primordial power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-25 Zong-Kuan Guo , Yuan-Zhong Zhang

Two years of microwave background observations with the Cosmic Background Imager (CBI) have been combined to give a sensitive, high resolution angular power spectrum over the range 400 < l < 3500. This power spectrum has been referenced to…

The angular power spectrum estimator developed by Peebles (1973) and Hauser & Peebles (1973) has been modified and applied to the 4 year maps produced by the COBE DMR. The power spectrum of the observed sky has been compared to the power…

Astrophysics · Physics 2008-11-26 E. L. Wright , C. L. Bennett , K. Gorski , G. Hinshaw , G. F. Smoot

We update the constraints on possible features in the primordial inflationary density perturbation spectrum by using the latest data from the WMAP7 and ACT Cosmic Microwave Background experiments. The inclusion of new data significantly…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Micol Benetti , Massimiliano Lattanzi , Erminia Calabrese , Alessandro Melchiorri

Potential features in the primordial power spectrum have been searched for in galaxy surveys in recent years since these features can assist in understanding the nature of inflation. The null detection to date suggests that any such…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-01 Yuhao Li , Hong-Ming Zhu , Baojiu Li

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

Astrophysics · Physics 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

We measure the skewness power spectrum of the Cosmic Microwave Background (CMB) anisotropies optimized for a detection of the secondary bispectrum generated by the correlation of the CMB lensing potential with integrated Sachs-Wolfe effect…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Erminia Calabrese , Joseph Smidt , Alexandre Amblard , Asantha Cooray , Alessandro Melchiorri , Paolo Serra , Alan Heavens , Dipak Munshi

Primordial features, in particular oscillatory signals, imprinted in the primordial power spectrum of density perturbations represent a clear window of opportunity for detecting new physics at high-energy scales. Future spectroscopic and…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-01 M. Ballardini , Y. Akrami , F. Finelli , D. Karagiannis , B. Li , Y. Li , Z. Sakr , D. Sapone , A. Achúcarro , M. Baldi , N. Bartolo , G. Cañas-Herrera , S. Casas , R. Murgia , H. A. Winther , M. Viel , A. Andrews , J. Jasche , G. Lavaux , D. K. Hazra , D. Paoletti , J. Valiviita , A. Amara , S. Andreon , N. Auricchio , P. Battaglia , D. Bonino , E. Branchini , M. Brescia , J. Brinchmann , S. Camera , V. Capobianco , C. Carbone , J. Carretero , M. Castellano , S. Cavuoti , A. Cimatti , G. Congedo , L. Conversi , Y. Copin , L. Corcione , F. Courbin , H. M. Courtois , A. Da Silva , H. Degaudenzi , F. Dubath , X. Dupac , M. Farina , S. Farrens , M. Frailis , E. Franceschi , M. Fumana , S. Galeotta , B. Gillis , C. Giocoli , A. Grazian , F. Grupp , S. V. H. Haugan , W. Holmes , F. Hormuth , A. Hornstrup , P. Hudelot , K. Jahnke , S. Kermiche , A. Kiessling , M. Kunz , H. Kurki-Suonio , P. B. Lilje , V. Lindholm , I. Lloro , E. Maiorano , O. Mansutti , O. Marggraf , N. Martinet , F. Marulli , R. Massey , E. Medinaceli , S. Mei , Y. Mellier , M. Meneghetti , E. Merlin , G. Meylan , M. Moresco , L. Moscardini , E. Munari , S. M. Niemi , C. Padilla , S. Paltani , F. Pasian , K. Pedersen , W. J. Percival , V. Pettorino , S. Pires , G. Polenta , M. Poncet , L. A. Popa , L. Pozzetti , F. Raison , A. Renzi , J. Rhodes , G. Riccio , E. Romelli , M. Roncarelli , R. Saglia , B. Sartoris , T. Schrabback , A. Secroun , G. Seidel , S. Serrano , C. Sirignano , G. Sirri , L. Stanco , J. L. Starck , C. Surace , P. Tallada-Crespí , A. N. Taylor , I. Tereno , R. Toledo-Moreo , F. Torradeflot , I. Tutusaus , E. A. Valentijn , L. Valenziano , T. Vassallo , A. Veropalumbo , Y. Wang , J. Weller , G. Zamorani , J. Zoubian , V. Scottez

In this paper, we focus our attention on the following question: How well can we recover the power spectrum of the cosmic microwave background from the maps of a given experiment?. Each experiment is described by a a pixelization scale, a…

Astrophysics · Physics 2016-08-15 D. Sáez , J. V. Arnau

The new three year WMAP data seem to confirm the presence of non-standard large scale features in the Cosmic Microwave Anisotropies power spectrum. While these features may hint at uncorrected experimental systematics, it is also possible…

Astrophysics · Physics 2009-11-11 Laura Covi , Jan Hamann , Alessandro Melchiorri , Anze Slosar , Irene Sorbera

We investigate the possibility of reconstructing the initial spectrum of density fluctuations from the cosmic microwave background (CMB) anisotropy. As a first step toward this program, we consider a spatially flat, CDM dominated universe.…

Astrophysics · Physics 2009-10-09 Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama