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Related papers: Approximating the Likelihood Function of CMB Exper…

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We discuss the constraints one can place on cosmological parameters using current cosmic microwave background data. A standard $\chi^2$--minimization over band--power estimates is first presented, followed by a discussion of the more…

Astrophysics · Physics 2007-05-23 J. G. Bartlett , A. Blanchard , M. Douspis , M. Le Dour

Band-power estimates of cosmic microwave background fluctuations are now routinely used to place constraints on cosmological parameters. For this to be done in a rigorous fashion, the full likelihood function of band-power estimates must be…

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

Most parameter constraints obtained from cosmic microwave background (CMB) anisotropy data are based on power estimates and rely on approximate likelihood functions; computational difficulties generally preclude an exact analysis based on…

Astrophysics · Physics 2009-11-06 M. Douspis , J. G. Bartlett , A. Blanchard , M. Le Dour

The majority of present efforts to constrain cosmological parameters with cosmic microwave background (CMB) anisotropy data employ approximate likelihood functions, the time consuming nature of a complete analysis being a major obstacle. We…

Astrophysics · Physics 2007-05-23 M. Douspis , J. G. Bartlett , A. Blanchard , M. Le Dour

Powerful constraints on theories can already be inferred from existing CMB anisotropy data. But performing an exact analysis of available data is a complicated task and may become prohibitively so for upcoming experiments with \gtrsim10^4…

Astrophysics · Physics 2009-10-30 J. R. Bond , A. H. Jaffe , L. E. Knox

Microwave background temperature and polarization observations are a powerful way to constrain cosmological parameters if the likelihood function can be calculated accurately. The temperature and polarization fields are correlated, partial…

Astrophysics · Physics 2012-04-25 Samira Hamimeche , Antony Lewis

The primary results of most observations of cosmic microwave background (CMB) anisotropy are estimates of the angular power spectrum averaged through some broad band, called band-powers. These estimates are in turn what are used to produce…

Astrophysics · Physics 2016-08-25 Lloyd Knox

Every experiment is affected by systematic effects that hamper the data analysis and have the potential to ultimately degrade its performance. In the case of probes of the cosmic microwave background (CMB) radiation, a minimal set of issues…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-08 Franz Elsner , Benjamin D. Wandelt

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

As the Cosmic Microwave Background (CMB) radiation is observed to higher and higher angular resolution the size of the resulting datasets becomes a serious constraint on their analysis. In particular current algorithms to determine the…

Astrophysics · Physics 2007-05-23 Julian Borrill

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

We develop two methods for estimating the power spectrum, C_l, of the cosmic microwave background (CMB) from data and apply them to the COBE/DMR and Saskatoon datasets. One method involves a direct evaluation of the likelihood function, and…

Astrophysics · Physics 2009-10-30 J. R. Bond , A. H. Jaffe , L. Knox

A great deal of experimental effort is currently being devoted to the precise measurements of the cosmic microwave background (CMB) sky in temperature and polarisation. Satellites, balloon-borne, and ground-based experiments scrutinize the…

Although the broad outlines of the appropriate pipeline for cosmological likelihood analysis with CMB data has been known for several years, only recently have we had to contend with the full, large-scale, computationally challenging…

Astrophysics · Physics 2009-11-10 Andrew H. Jaffe , J. R. Bond , P. G. Ferreira , L. E. Knox

Application of a Goodness--of--fit (GOF) statistic is an essential element of parameter estimation. We discuss the computation of GOF when estimating parameters from anisotropy measurements of the cosmic microwave background (CMB), and we…

Astrophysics · Physics 2009-11-07 M. Douspis , J. G. Bartlett , A. Blanchard

A maximum-likelihood method is presented for estimating the power spectrum of anisotropies in the cosmic microwave background (CMB) from interferometer observations. The method calculates flat band-power estimates in separate bins in…

Astrophysics · Physics 2009-11-07 M. P. Hobson , Klaus Maisinger

Accurate parameter estimation from cosmic microwave background data requires reliable likelihood modeling, particularly at large angular scales where angular power spectrum estimators exhibit non-Gaussian statistics. We present a novel…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Giacomo Galloni , Paolo Campeti , Luca Pagano , Martina Gerbino , Massimiliano Lattanzi , Paolo Natoli

Fast robust methods for calculating likelihoods from CMB observations on small scales generally rely on approximations based on a set of power spectrum estimators and their covariances. We investigate the optimality of these approximation,…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Samira Hamimeche , Antony Lewis

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 controlled approximations or are…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…

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