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Related papers: Catalog-based pseudo-$C_\ell$s

200 papers

Weak lensing surveys are often summarized by constraints on the derived parameter ${S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}}$, obscuring the rich scale and redshift information encoded in the data, and limiting our ability to identify…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-08 Cyrille Doux , Tanvi Karwal

The tangential shear signal receives contributions from physical scales in the galaxy-matter correlation function well below the transverse scale at which it is measured. Since small scales are difficult to model, this non-locality has…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-23 Niall MacCrann , Jonathan Blazek , Bhuvnesh Jain , Elisabeth Krause

We present a new efficient method to compute the angular power spectra of large-scale structure observables that circumvents the numerical integration over Bessel functions, expanding on a recently proposed algorithm based on FFTlog. This…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-31 Nils Schöneberg , Marko Simonović , Julien Lesgourgues , Matias Zaldarriaga

Obtaining constraints from the largest scales of a galaxy survey is challenging due to the survey mask allowing only partial measurement of large angular modes. This scatters information from the harmonic-space 2-point function away from…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-16 Henry S. Grasshorn Gebhardt , Olivier Doré

We extend the pure pseudo-power-spectrum formalism proposed recently in the context of the Cosmic Microwave Background polarized power spectra estimation by Smith (2006) to incorporate cross-spectra computed for multiple maps of the same…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-09 J. Grain , M. Tristram , R. Stompor

We develop a practical methodology to remove modes from a galaxy survey power spectrum that are associated with systematic errors. We apply this to the BOSS CMASS sample, to see if it removes the excess power previously observed beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-25 B. Bahr-Kalus , W. J. Percival , D. J. Bacon , E. -M. Mueller , L. Samushia , L. Verde , A. J. Ross , J. L. Bernal

Cosmic shear tomography has emerged as one of the most promising tools to both investigate the nature of dark energy and discriminate between General Relativity and modified gravity theories. In order to successfully achieve these goals,…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 V. F. Cardone , M. Martinelli , E. Calabrese , S. Galli , Z. Huang , R. Maoli , A. Melchiorri , R. Scaramella

We derive a general ansatz for optimizing pseudo-C_l estimators used to measure CMB anisotropy power spectra, and apply it to the recently-proposed pure pseudo-C_l formalism, to obtain an estimator which achieves near-optimal B-mode power…

Astrophysics · Physics 2008-11-26 Kendrick M. Smith , Matias Zaldarriaga

We estimate the sensitivity of future galaxy surveys to cosmological parameters, using the redshift dependent angular power spectra of galaxy number counts, $C_\ell(z_1,z_2)$, calculated with all relativistic corrections at first order in…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-04 Enea Di Dio , Francesco Montanari , Ruth Durrer , Julien Lesgourgues

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

Astrophysics · Physics 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

We present the first step toward deriving cosmological constraints through the abundances of galaxy clusters selected in a $510\,\mathrm{deg}^2$ weak-lensing aperture mass map, constructed with the Year-Three shear catalog from the Hyper…

Inference in cosmology often starts with noisy observations of random fields on the celestial sphere, such as maps of the microwave background radiation, continuous maps of cosmic structure in different wavelengths, or maps of point tracers…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 E. Sellentin , A. Loureiro , L. Whiteway , J. S. Lafaurie , S. T. Balan , M. Olamaie , A. H. Jaffe , A. F. Heavens

Cosmic shear is one of the most powerful probes of Dark Energy, targeted by several current and future galaxy surveys. Lensing shear, however, is only sampled at the positions of galaxies with measured shapes in the catalog, making its…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Andrina Nicola , Carlos García-García , David Alonso , Jo Dunkley , Pedro G. Ferreira , Anže Slosar , David N. Spergel

We investigate cosmological parameter inference from realistic simulated weak lensing image data using only galaxy position angles, as opposed to full-ellipticity information. We demonstrate that input shear fields can be accurately…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-30 Lee Whittaker

An accurate covariance matrix is essential for obtaining reliable cosmological results when using a Gaussian likelihood. In this paper we study the covariance of pseudo-$C_\ell$ estimates of tomographic cosmic shear power spectra. Using two…

Estimation of the angular power spectrum of the Cosmic Microwave Background (CMB) on a small patch of sky is usually plagued by serious spectral leakage, specially when the map has a hard edge. Even on a full sky map, point source masks can…

Astrophysics · Physics 2009-11-06 Sudeep Das , Amir Hajian , David N. Spergel

We propose and implement a fast, universally applicable method for extracting the angular power spectrum C_l from CMB temperature maps by first estimating the correlation function \xi(\theta). Our procedure recovers the C_l's using N^2 (but…

We compute the effects induced by the use of small CMB maps on the measurement of the $\cl{l}$ coefficients of the angular power spectrum and show that small systematic effects have to be taken into account. We also compute numerically the…

Astrophysics · Physics 2007-08-06 C. Magneville , J. P. Pansart