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We develop a method for performing a weak lensing analysis using only measurements of galaxy position angles. By analysing the statistical properties of the galaxy orientations given a known intrinsic ellipticity distribution, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Lee Whittaker , Michael L. Brown , Richard Battye

We re-examine a genuine power of weak lensing bispectrum tomography for constraining cosmological parameters, when combined with the power spectrum tomography, based on the Fisher information matrix formalism. To account for the full…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-21 Issha Kayo , Masahiro Takada

Weak gravitational lensing induces flux dependent fluctuations in the observed galaxy number density distribution. This cosmic magnification (magnification bias) effect in principle enables lensing reconstruction alternative to cosmic shear…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Ruijie Ma , Pengjie Zhang , Yu Yu , Jian Qin

Standard cosmological weak lensing analyses using cosmic shear are inevitably sensitive to small-scale, non-linear clustering from low-redshift structures. The need to adequately model the clustering of matter on this non-linear regime,…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-25 Giulia Piccirilli , Matteo Zennaro , Carlos García-García , David Alonso

Photo-z errors, especially catastrophic errors, are a major uncertainty for precision weak lensing cosmology. We find that the shear-(galaxy number) density and density-density cross correlation measurements between photo-z bins, available…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Pengjie Zhang , Ue-Li Pen , Gary Bernstein

We investigate the use of the Multiple Optimised Parameter Estimation and Data compression algorithm (MOPED) for data compression and faster evaluation of likelihood functions. Since MOPED only guarantees maintaining the Fisher matrix of…

Instrumentation and Methods for Astrophysics · Physics 2011-05-17 Philip Graff , Mike Hobson , Anthony Lasenby

Optimization of sensor selection has been studied to monitor complex and large-scale systems with data-driven linear reduced-order modeling. An algorithm for greedy sensor selection is presented under the assumption of correlated noise in…

Signal Processing · Electrical Eng. & Systems 2022-07-14 Keigo Yamada , Yuji Saito , Taku Nonomura , Keisuke Asai

Cosmological inference from cluster number counts is systematically limited by the accuracy of the mass calibration, i.e. the empirical determination of the mapping between cluster selection observables and halo mass. In this work we…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-21 Sebastian Grandis , Sebastian Bocquet , Joseph J. Mohr , Matthias Klein , Klaus Dolag

We present the results of weak gravitational lensing statistics in four different cosmological $N$-body simulations. The data has been generated using an algorithm for the three-dimensional shear, which makes use of a variable softening…

Astrophysics · Physics 2009-10-31 Andrew J. Barber , Peter A. Thomas , H. M. P. Couchman , C. J. Fluke

Upcoming surveys such as \LSST{} and \Euclid{} will significantly improve the power of weak lensing as a cosmological probe. To maximise the information that can be extracted from these surveys, it is important to explore novel statistics…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Christopher T. Davies , Marius Cautun , Benjamin Giblin , Baojiu Li , Joachim Harnois-Déraps , Yan-Chuan Cai

We investigate the prospects for using the weak lensing bispectrum alongside the power spectrum to control systematic uncertainties in a Euclid-like survey. Three systematic effects are considered: the intrinsic alignment of galaxies,…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-02 Susan Pyne , Benjamin Joachimi

Weakly supervised image segmentation approaches in the literature usually achieve high segmentation performance using tight bounding box supervision and decrease the performance greatly when supervised by loose bounding boxes. However,…

Computer Vision and Pattern Recognition · Computer Science 2023-01-31 Juan Wang , Bin Xia

We advocate an optimization procedure for variable density sampling in the context of compressed sensing. In this perspective, we introduce a minimization problem for the coherence between the sparsity and sensing bases, whose solution…

Information Theory · Computer Science 2011-09-29 Gilles Puy , Pierre Vandergheynst , Yves Wiaux

In cosmology, we routinely choose between models to describe our data, and can incur biases due to insufficient models or lose constraining power with overly complex models. In this paper we propose an empirical approach to model selection…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 Andresa Campos , Simon Samuroff , Rachel Mandelbaum

The success of future large scale weak lensing surveys will critically depend on the accurate estimation of photometric redshifts of very large samples of galaxies. This in turn depends on both the quality of the photometric data and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 R. Bordoloi , S. J. Lilly , A. Amara , P. A. Oesch , S. Bardelli , E. Zucca , D. Vergani , T. Nagao , T. Murayama , Y. Shioya , Y. Taniguchi

Calibrating photometric redshift errors in weak lensing surveys with external data is extremely challenging. We show that both Gaussian and outlier photo-z parameters can be self-calibrated from the data alone. This comes at no cost for the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-22 Emmanuel Schaan , Simone Ferraro , Uroš Seljak

Galaxy clusters are usually detected in blind optical surveys via suitable filtering methods. We present an optimal matched filter which maximizes their signal-to-noise ratio by taking advantage of the knowledge we have of their intrinsic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Fabio Bellagamba , Matteo Maturi , Takashi Hamana , Massimo Meneghetti , Satoshi Miyazaki , Lauro Moscardini

We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a spatial process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Michael D. Schneider , Karen Y. Ng , William A. Dawson , Philip J. Marshall , Joshua Meyers , Deborah J. Bard

The statistics of peaks in weak gravitational lensing maps is a promising technique to constrain cosmological parameters in present and future surveys. Here we investigate its power when using general extreme value statistics which is very…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-12 Robert Reischke , Matteo Maturi , Matthias Bartelmann

Measuring weak lensing cosmic magnification signal is very challenging due to the overwhelming intrinsic clustering in the observed galaxy distribution. In this paper, we modify the Internal Linear Combination (ILC) method to reconstruct…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-13 Shutong Hou , Yu Yu , Pengjie Zhang
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