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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

The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…

The CMB anisotropy depends sensitively upon the slope and amplitude of primordial density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, {\it etc.} We report…

Astrophysics · Physics 2009-09-25 J. Richard Bond , Richard L. Davis , Paul J. Steinhardt

Recently funded satellites will map the cosmic microwave background radiation with unprecedented sensitivities and angular resolutions. Assuming only primordial adiabatic scalar and tensor perturbations, we evaluate how accurately…

Astrophysics · Physics 2009-10-28 Arthur Kosowsky , Marc Kamionkowski , Gerard Jungman , David N. Spergel

The redshift dependence of the abundance of galaxy clusters is very sensitive to the statistical properties of primordial density perturbations. It can thus be used to probe small deviations from Gaussian initial conditions. Such deviations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 A. M. M. Trindade , P. P. Avelino , P. T. P. Viana

The likelihood function is a crucial element of parameter estimation. In analyses of galaxy overdensities and weak lensing shear, one often approximates the likelihood of the power spectrum with a Gaussian distribution. The posterior…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 L. Sun , Q. Wang , H. Zhan

We revisit the issue of cosmological parameter estimation in light of current and upcoming high-precision measurements of the cosmic microwave background power spectrum. Physical quantities which determine the power spectrum are reviewed,…

Astrophysics · Physics 2009-11-07 Arthur Kosowsky , Milos Milosavljevic , Raul Jimenez

Recently high quality data of the cosmic microwave background anisotropies have been published. In this work we study to which extent the cosmological parameters determined by using this data depend on assumptions about the initial…

Astrophysics · Physics 2009-11-06 R. Trotta , A. Riazuelo , R. Durrer

In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or from simulations), its underlying cosmology should not…

Astrophysics · Physics 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

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 present a unified semi-analytic framework…

Astrophysics · Physics 2009-10-30 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

We review the basic hypotheses which motivate the statistical framework used to analyze the cosmic microwave background, and how that framework can be enlarged as we relax those hypotheses. In particular, we try to separate as much as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 L. Raul Abramo , Thiago S. Pereira

The spectrum and statistics of the cosmic microwave background radiation (CMBR) are investigated under the hypothesis that scale invariance of the primordial density fluctuations should be promoted to full conformal invariance. As in the…

Astrophysics · Physics 2008-11-26 I. Antoniadis , P. O. Mazur , E. Mottola

We investigate the cosmic variance of the skewness of the cosmic microwave background (CMB) anisotropies in an inflationary model which leads to the baryon isocurvature scenario for the cosmic structure formation. In this model, the baryon…

Astrophysics · Physics 2016-08-30 Kazuhiro Yamamoto , Misao Sasaki

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark…

Astrophysics · Physics 2016-01-13 J. Richard Bond , George Efstathiou , Max Tegmark

Recent estimates of cosmological parameters derived from Cosmic Microwave Background (CMB) anisotropies are based on the assumption that we know the precise amount of energy density in relativistic particles in the universe, $\omega_{rel}$,…

Astrophysics · Physics 2008-11-26 R. Bowen , S. H. Hansen , A. Melchiorri , J. Silk , R. Trotta

The angular power spectrum of the cosmic microwave background (CMB) contains information on virtually all cosmological parameters of interest, including the geometry of the Universe ($\Omega$), the baryon density, the Hubble constant ($h$),…

Astrophysics · Physics 2009-10-28 Gerard Jungman , Marc Kamionkowski , Arthur Kosowsky , David N. Spergel

Accurate estimation of cosmological parameters from microwave background anisotropies requires high-accuracy understanding of the cosmological model. Normally, a power-law spectrum of density perturbations is assumed, in which case the…

Astrophysics · Physics 2009-10-30 Edmund J Copeland , Ian J Grivell , Andrew R Liddle

The estimation of cosmological parameters from a given data set requires a construction of a likelihood function which, in general, has a complicated functional form. We adopt a Gaussian copula and constructed a copula likelihood function…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-28 Masanori Sato , Kiyotomo Ichiki , Tsutomu T. Takeuchi

Skewness of temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational…

Astrophysics · Physics 2009-10-28 Dipak Munshi , Tarun Souradeep , Alexei A. Starobinsky

The most direct probe of non-Gaussian initial conditions has come from bispectrum measurements of temperature fluctuations in the Cosmic Microwave Background and of the matter and galaxy distribution at large scales. Such bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Liguori , E. Sefusatti , J. R. Fergusson , E. P. S. Shellard
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