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Related papers: CMB spectra and bispectra calculations: making the…

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Estimation of the sky signal from sequences of time ordered data is one of the key steps in Cosmic Microwave Background (CMB) data analysis, commonly referred to as the map-making problem. Some of the most popular and general methods…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-16 Mikolaj Szydlarski , Laura Grigori , Radek Stompor

Measurement of the cosmic microwave background (CMB) bispectrum, or three-point correlation function, has now become one of the principle efforts in early-Universe cosmology. Here we show that there is a odd-parity component of the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Marc Kamionkowski , Tarun Souradeep

The angular two-point correlation function of the temperature of the cosmic microwave background (CMB), as inferred from nearly all-sky maps, is very close to zero on large angular scales. A statistic invented to quantify this feature,…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-04 Robert Knight , Lloyd Knox

Following the recent measurement of the acoustic peak by the BOOMERanG and MAXIMA experiments in the CMB anisotropy angular power spectrum, many analyses have found that the geometry of the Universe is very close to flat, but slightly…

Astrophysics · Physics 2009-10-31 Alessandro Melchiorri , Louise M. Griffiths

We present trispectrum estimation methods which can be applied to general non-separable primordial and CMB trispectra. We present a general optimal estimator for the connected part of the trispectrum, for which we derive a quadratic term to…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 D. M. Regan , E. P. S. Shellard , J. R. Fergusson

The frequency spectrum of the cosmic microwave background (CMB) is a relatively untapped source of data which can allow us to peer beyond the surface of last scattering. Small deviations away from a perfect blackbody shape will encode…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-21 Bryce Cyr

Hu [Phys. Rev. D62 (2000) 043007] has presented a harmonic-space method for calculating the effects of weak gravitational lensing on the cosmic microwave background (CMB) over the full sky. Computing the lensed power spectra to first order…

Astrophysics · Physics 2009-11-07 Anthony Challinor , Gayoung Chon

In this paper we report on recent results by several authors, on the spectral theory of lens spaces and orbifolds and similar locally symmetric spaces of rank one. Most of these results are related to those obtained by the authors in [IMRN…

Differential Geometry · Mathematics 2021-08-11 Emilio A. Lauret , Roberto J. Miatello , Juan Pablo Rossetti

We present a determination of the bispectrum of the flux in the Lyman-alpha forest of QSO absorption spectra obtained from LUQAS which consists of spectra observed with the high resolution Echelle spectrograph UVES. Typical errors on the…

Astrophysics · Physics 2009-11-10 M. Viel , S. Matarrese , A. Heavens , M. G. Haehnelt , T. -S. Kim , V. Springel , L. Hernquist

The CMB is a powerful probe of early-universe physics but is only observed after passing through large-scale structure, which changes the observed spectra in important model-dependent ways. This is of particular concern given recent claims…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-17 Pablo Lemos , Antony Lewis

Clustering of large-scale structure provides significant cosmological information through the power spectrum of density perturbations. Additional information can be gained from higher-order statistics like the bispectrum, especially to…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-09 Marcel Schmittfull , Tobias Baldauf , Uroš Seljak

The Planck experiment has measured the Cosmic Microwave Background (CMB) angular spectrum with unprecedented accuracy, and these results are likely to remain the state-of-the art for a decade or more. Since these measurements are going to…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 Julia Stadler , Céline Bœhm

The locations of the peaks of the CMB spectrum are sensitive indicators of cosmological parameters, yet there is no known analytic formula which accurately describes their dependence on them. We parametrize the location of the peaks as l_m…

Astrophysics · Physics 2008-11-26 Michael Doran , Matthew Lilley

We introduce two kurt-spectra to probe fourth-order statistics of weak lensing convergence maps. Using state-of-the-art numerical simulations, we study the shapes of these kurt-spectra as a function of source redshifts and smoothing angular…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-16 Dipak Munshi , Hayden Lee , Cora Dvorkin , Jason D. McEwen

Modelling of the weak lensing of the CMB will be crucial to obtain correct cosmological parameter constraints from forthcoming precision CMB anisotropy observations. The lensing affects the power spectrum as well as inducing…

Astrophysics · Physics 2010-11-17 Antony Lewis

The study of third-order statistics in large-scale structure analyses has been hampered by the increased complexity of bispectrum estimators (compared to power spectra), the large dimensionality of the data vector, and the difficulty in…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-20 Lea Harscouet , Jessica A. Cowell , Julia Ereza , David Alonso , Hugo Camacho , Andrina Nicola , Anže Slosar

We identify a connection between the approximability of CSPs in two models: (i) sublinear space streaming algorithms, and (ii) the basic LP relaxation. We show that whenever the basic LP admits an integrality gap, there is an…

Computational Complexity · Computer Science 2025-09-23 Noah G. Singer , Madhur Tulsiani , Santhoshini Velusamy

We present an efficient separable approach to the estimation and reconstruction of the bispectrum and the trispectrum from observational (or simulated) large scale structure data. This is developed from general CMB (poly-)spectra methods…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 J. R. Fergusson , D. M. Regan , E. P. S. Shellard

Spectral clustering is a broad class of clustering procedures in which an intractable combinatorial optimization formulation of clustering is "relaxed" into a tractable eigenvector problem, and in which the relaxed solution is subsequently…

Methodology · Statistics 2011-02-21 Zhihua Zhang , Michael I. Jordan