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Baryonic feedback effects lead to a suppression of the weak lensing angular power spectrum on small scales. The poorly constrained shape and amplitude of this suppression is an important source of uncertainties for upcoming cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-29 Aurel Schneider , Nicola Stoira , Alexandre Refregier , Andreas J. Weiss , Mischa Knabenhans , Joachim Stadel , Romain Teyssier

Third-order weak lensing statistics are a promising tool for cosmological analyses since they extract cosmological information in the non-Gaussianity of the cosmic large-scale structure. However, such analyses require precise and accurate…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Laila Linke , Sven Heydenreich , Pierre A. Burger , Peter Schneider

Increasingly large parameter spaces, used to more accurately model precision observables in physics, can paradoxically lead to large deviations in the inferred parameters of interest -- a bias known as volume projection effects -- when…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-29 Alexander Reeves , Pierre Zhang , Henry Zheng

In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jan Harms , Christoph Mahrdt , Markus Otto , Malte Priess

Map-making presents a significant computational challenge to the next generation of kilopixel CMB polarisation experiments. Years worth of time ordered data (TOD) from thousands of detectors will need to be compressed into maps of the T, Q…

Astrophysics · Physics 2009-02-16 D. Sutton , B. R. Johnson , M. L. Brown , P. Cabella , P. G. Ferreira , K. M. Smith

Ground and space-based sky surveys enable powerful cosmological probes based on measurements of galaxy properties and the distribution of galaxies in the Universe. These probes include weak lensing, baryon acoustic oscillations, abundance…

We perform a detailed analysis of the covariance matrix of the spherically averaged galaxy power spectrum and present a new, practical method for estimating this within an arbitrary survey without the need for running mock galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-18 Cullan Howlett , Will J. Percival

We consider high-dimensional measurement errors with high-frequency data. Our objective is on recovering the high-dimensional cross-sectional covariance matrix of the random errors with optimality. In this problem, not all components of the…

Statistics Theory · Mathematics 2024-04-03 Jinyuan Chang , Qiao Hu , Cheng Liu , Cheng Yong Tang

We present a new method, called $x$-cut cosmic shear, which optimally removes sensitivity to poorly modeled scales from the two-point cosmic shear signal. We show that the $x$-cut cosmic shear covariance matrix can be computed from the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 Peter L. Taylor , Francis Bernardeau , Eric Huff

We present a fast and robust alternative method to compute covariance matrix in case of cosmology studies. Our method is based on the jackknife resampling applied on simulation mock catalogues. Using a set of 600 BOSS DR11 mock catalogues…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-02 S. Escoffier , M. -C. Cousinou , A. Tilquin , A. Pisani , A. Aguichine , S. de la Torre , A. Ealet , W. Gillard , E. Jullo

Using the Reduced Basis approach, we efficiently compress and accurately represent the space of waveforms for non-precessing binary black hole inspirals, which constitutes a four dimensional parameter space (two masses, two spin…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Frank Herrmann , Scott E. Field , Chad R. Galley , Evan Ochsner , Manuel Tiglio

Constraining cosmology using weak gravitational lensing consists of comparing a measured feature vector of dimension $N_b$ with its simulated counterpart. An accurate estimate of the $N_b\times N_b$ feature covariance matrix $\mathbf{C}$ is…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-28 Andrea Petri , Zoltán Haiman , Morgan May

With the advent of large-scale weak lensing surveys there is a need to understand how realistic, scale-dependent systematics bias cosmic shear and dark energy measurements, and how they can be removed. Here we describe how spatial…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-31 A. N. Taylor , T. D. Kitching

Deep learning is a powerful analysis technique that has recently been proposed as a method to constrain cosmological parameters from weak lensing mass maps. Due to its ability to learn relevant features from the data, it is able to extract…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 Janis Fluri , Tomasz Kacprzak , Aurelien Lucchi , Alexandre Refregier , Adam Amara , Thomas Hofmann

Forthcoming cosmic shear surveys will make precise measurements of the matter density field down to very small scales, scales which are dominated by baryon feedback. The modelling of baryon feedback is crucial to ensure unbiased…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Alessandro Maraio , Alex Hall , Andy Taylor

We use the full-sky ray-tracing weak lensing simulations to generate 2268 mock catalogues for the Subaru Hyper Suprime-Cam (HSC) survey first-year shear catalogue. Our mock catalogues take into account various effects as in the real data:…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Masato Shirasaki , Takashi Hamana , Masahiro Takada , Ryuichi Takahashi , Hironao Miyatake

One of the main unsolved problems of cosmology is how to maximize the extraction of information from nonlinear data. If the data are nonlinear the usual approach is to employ a sequence of statistics (N-point statistics, counting statistics…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 Uros Seljak , Grigor Aslanyan , Yu Feng , Chirag Modi

We present an approach for accurate estimation of the covariance of 2-point correlation functions that requires fewer mocks than the standard mock-based covariance. This can be achieved by dividing a set of mocks into jackknife regions and…

We present an algorithm for quickly generating multiple realizations of N-body simulations to be used, for example, for cosmological parameter estimation from surveys of large-scale structure. Our algorithm uses a new method to resample the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael D. Schneider , Shaun Cole , Carlos S. Frenk , Istvan Szapudi
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