English
Related papers

Related papers: Shear Power Spectrum Reconstruction using Pseudo-S…

200 papers

We present new results on the gravitational lensing shear and magnification power spectra obtained from numerical simulations of a flat cosmology with a cosmological constant. These results are of considerable interest since both the shear…

Astrophysics · Physics 2009-11-07 Andrew J. Barber , A. N. Taylor

We propose a new strategy to probe the power spectrum on large scales using galaxy peculiar velocities. We explore the properties of surveys that cover only two small fields in opposing directions on the sky. Surveys of this type have…

Astrophysics · Physics 2009-10-30 Hume A. Feldman , Richard Watkins

We develop an accurate and efficient Bayesian method to reconstruct the primordial power spectrum in a model-independent way, and apply it to the latest cosmic microwave background measurement from Planck mission, and the large scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-28 Xin Wang , Gong-Bo Zhao

We apply two sparse reconstruction techniques, the least absolute shrinkage and selection operator (LASSO) and the sparse exponential mode analysis (SEMA), to two-dimensional (2D) spectroscopy. The algorithms are first tested on model data,…

Signal Processing · Electrical Eng. & Systems 2020-07-01 Zhengjun Wang , Shiwen Lei , Khadga Jung Karki , Andreas Jakobsson , Tönu Pullerits

We present a generalisation of the standard pseudo-$C_\ell$ approach for power spectrum estimation to the case of spin-$s$ fields weighted by a general positive-definite weight matrix that couples the different spin components of the field…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-05 David Alonso

It is commonplace in cosmology to analyze fields projected onto the celestial sphere, and in particular density fields that are defined by a set of points e.g. galaxies. When performing an harmonic-space analysis of such data (e.g. an…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-02 Antón Baleato Lizancos , Martin White

We present new methods for lensing reconstruction from CMB temperature fluctuations which have smaller mean-field and reconstruction noise bias corrections than current lensing estimators, with minimal loss of signal-to-noise. These biases…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 Toshiya Namikawa , Duncan Hanson , Ryuichi Takahashi

The observable universe contains density perturbations on scales larger than any finite volume survey. Perturbations on scales larger than a survey can measure degrade its power to constrain cosmological parameters. The dependence of survey…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-09 Matthew C. Digman , Joseph E. McEwen , Christopher M. Hirata

Large-scale structure distorts the images of background galaxies, which allows one to measure directly the projected distribution of dark matter in the universe and determine its power spectrum. Here we address the question of how to…

Astrophysics · Physics 2009-10-30 Uros Seljak

Upcoming wide field surveys will have many overlapping epochs of the same region of sky. The conventional wisdom is that in order to reduce the errors sufficiently for systematics-limited measurements, like weak lensing, we must do…

Weak lensing of CMB anisotropies and polarization for the power spectra and higher order statistics can be handled directly in harmonic-space without recourse to real-space correlation functions. For the power spectra, this approach not…

Astrophysics · Physics 2009-10-31 Wayne Hu

A method for extracting maximal resolution power spectra from microwave sky maps is presented and applied to the 2 year COBE data, yielding a power spectrum that is consistent with a standard n=1, Q=20 micro-Kelvin model. By using weight…

Astrophysics · Physics 2015-06-24 Max Tegmark

We present a formalism to extract the angular power spectrum of fields sampled at a finite number of points with arbitrary positions -- a common situation for several catalog-based astrophysical probes -- through a simple extension of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 Kevin Wolz , David Alonso , Andrina Nicola

Recovering shadows is an important step for many vision algorithms. Current approaches that work with time-lapse sequences are limited to simple thresholding heuristics. We show these approaches only work with very careful tuning of…

Computer Vision and Pattern Recognition · Computer Science 2013-04-16 Austin Abrams , Chris Hawley , Kylia Miskell , Adina Stoica , Nathan Jacobs , Robert Pless

Recent work has developed a formalism for computing angular power spectra directly from catalogues containing field values at discrete positions on the sky, thereby circumventing the need to create pixelised maps of the fields, as well as…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Thomas Cornish , David Alonso , Boris Leistedt , Kevin Wolz

We present a joint weak lensing and X-ray analysis of 4 deg$^2$ from the CFHTLS and XMM-LSS surveys. Our weak lensing analysis is the first analysis of a real survey using shapelets, a new generation weak lensing analysis method. We create…

We present a Bayesian hierarchical modelling approach to infer the cosmic matter density field, and the lensing and the matter power spectra, from cosmic shear data. This method uses a physical model of cosmic structure formation to infer…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Natalia Porqueres , Alan Heavens , Daniel Mortlock , Guilhem Lavaux

We construct a pipeline for simulating weak lensing cosmology surveys with the Square Kilometre Array (SKA), taking as inputs telescope sensitivity curves; correlated source flux, size and redshift distributions; a simple ionospheric model;…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Anna Bonaldi , Ian Harrison , Stefano Camera , Michael L. Brown

The power spectrum of density fluctuations measured from galaxy redshift surveys provides important constraints on models for the formation of large-scale structure. I review current results for the 3-D power spectrum and examine the…

Astrophysics · Physics 2007-05-23 Michael S. Vogeley

Precision measurements of the galaxy power spectrum P(k) require a data analysis pipeline that is both fast enough to be computationally feasible and accurate enough to take full advantage of high-quality data. We present a rigorous…

Astrophysics · Physics 2009-10-07 Max Tegmark , Andrew Hamilton , Michael Strauss , Michael Vogeley , Alexander Szalay
‹ Prev 1 4 5 6 7 8 10 Next ›