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We propose a rigorous, non-perturbative, Bayesian framework which enables one jointly to test Gaussianity and estimate the power spectrum of CMB anisotropies. It makes use of the Hilbert space of an harmonic oscillator to set up an exact…

Astrophysics · Physics 2009-10-31 Graca Rocha , Joao Magueijo , Mike Hobson , Anthony Lasenby

In this paper we propose a new statistic capable of detecting non-Gaussianity in the CMB. The statistic is defined in Fourier space, and therefore naturally separates angular scales. It consists of taking another Fourier transform, in…

Astrophysics · Physics 2010-04-08 Alex Lewin , Andreas Albrecht , Joao Magueijo

Skew-spectra allow us to extract non-Gaussian information by taking the square of a map and finding the power spectrum of this new map with the original map. This allows us to use much of the infrastructure of power spectra and avoid the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 Alexander Roskill , Sara Maleubre , David Alonso , Pedro G. Ferreira

In the era of high precision CMB measurements, systematic effects are beginning to limit the ability to extract subtler cosmological information. The non-circularity of the experimental beam has become progressively important as CMB…

Astrophysics · Physics 2011-04-11 Tarun Souradeep , Sanjit Mitra , Anand Sengupta , Subharthi Ray , Rajib Saha

Using the Boltzmann equation with a Langevin-like term describing the stochastic force in a baryon-photon plasma, we investigate the influence of the incoherent electron-photon scattering on the subhorizon evolution of the cosmic microwave…

Astrophysics · Physics 2007-05-23 Li-Zhi Fang , Zheng Huang , Xian-Ping Wu

Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological models and parameters. However, precision can only be meaningful…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 Santanu Das , Sanjit Mitra , Sonu Tabitha Paulson

Likelihood fitting to two-point clustering statistics made from galaxy surveys usually assumes a multivariate normal distribution for the measurements, with justification based on the central limit theorem given the large number of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Mike Shengbo Wang , Will J. Percival , Santiago Avila , Robert Crittenden , Davide Bianchi

We approximately compute the bispectrum induced on the CMB temperature by fluctuations in the standard recombination epoch. Of all the second order sources that can induce non-Gaussianity during recombination, we concentrate on those…

Astrophysics · Physics 2009-10-02 Leonardo Senatore , Svetlin Tassev , Matias Zaldarriaga

The marked power spectrum is capable of placing far tighter constraints on cosmological parameters (particularly the neutrino mass) than the conventional power spectrum. What new information does it contain beyond conventional statistics?…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Oliver H. E. Philcox , Elena Massara , David N. Spergel

The primary science driver for 3D galaxy surveys is their potential to constrain cosmological parameters. Forecasts of these surveys' effectiveness typically assume Gaussian statistics for the underlying matter density, despite the fact…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-27 Andrew Repp , István Szapudi , Julien Carron , Melody Wolk

The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, {\it i.e.} aberration, and a shift in their frequency, {\it i.e.} Doppler effect. Both effects distort the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Riccardo Catena , Alessio Notari

We present a method for measuring CMB polarization power spectra given incomplete sky coverage and test it with simulated examples such as Boomerang 2001 and MAP. By augmenting the quadratic estimator method with an additional step, we find…

Astrophysics · Physics 2009-10-07 Max Tegmark , Angelica de Oliveira-Costa

This contribution discusses isocurvature modes, in particular the non-Gaussianities of local type generated by these modes. Since the isocurvature transfer functions differ from the adiabatic one, the coexistence of a primordial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 David Langlois

After the precise observations of the Cosmic Microwave Background (CMB) anisotropy power spectrum, attention is now being focused on the higher order statistics of the CMB anisotropies. Since linear evolution preserves the statistical…

Astrophysics · Physics 2009-11-10 Daniel Babich , Matias Zaldarriaga

CMB anisotropies are modified by the weak lensing effect of intervening large scale structures on the photon path from the last scattering surface to the observer. This has to be accounted for when observational data of sensitive…

Astrophysics · Physics 2010-10-27 Jonathan Rocher , Karim Benabed , Francois Bouchet

The detection of primordial non-Gaussianity could provide a powerful means to test various inflationary scenarios. Although scale-invariant non-Gaussianity (often described by the $f_{NL}$ formalism) is currently best constrained by the…

Astrophysics · Physics 2009-06-23 Marilena LoVerde , Amber Miller , Sarah Shandera , Licia Verde

We examine Cosmic Microwave Background (CMB) temperature power spectra from the BOOMERANG, MAXIMA, and DASI experiments. We non-parametrically estimate the true power spectrum with no model assumptions. This is a significant departure from…

In this work we examine the impact of our motion with respect to the CMB rest frame on statistics of CMB maps by examining the one-, two-, three- and four- point statistics of simulated maps of the CMB and Sunyaev-Zeldovich (SZ) effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 William R. Coulton , Sydney Feldman , Karime Maamari , Elena Pierpaoli , Siavash Yasini , Klaus Dolag

The determination of a steeply falling energy spectrum from rare events with non-gaussian measurement errors is a delicate matter. The final shape of the spectrum may be severely distorted as a consequence of non-gaussian tails in the…

Astrophysics · Physics 2007-05-23 C. O. Escobar , L. G. dos Santos , R. A. Vazquez

Analytic expressions for the statistics of peaks of random fields with weak non-Gaussianity are provided. Specifically, the abundance and spatial correlation of peaks are represented by formulas which can be evaluated only by virtually…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Takahiko Matsubara