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Analyzes of next-generation galaxy data require accurate treatment of systematic effects such as the bias between observed galaxies and the underlying matter density field. However, proposed models of the phenomenon are either numerically…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Guilhem Lavaux , Jens Jasche

The abundance and mass distribution of galaxy clusters is a sensitive probe of cosmological parameters, through the sensitivity of the high-mass end of the halo mass function to $\Omega_m$ and $\sigma_8$. While galaxy cluster surveys have…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 M. Regamey , D. Eckert , R. Seppi , W. Hartley , K. Umetsu , S. Tam , D. Gerolymatou

Recently, sparsity-based algorithms are proposed for super-resolution spectrum estimation. However, to achieve adequately high resolution in real-world signal analysis, the dictionary atoms have to be close to each other in frequency,…

Machine Learning · Statistics 2015-06-05 Yiyuan She , Huanghuang Li , Jiangping Wang , Dapeng Wu

Bayesian hierarchical models have been demonstrated to provide efficient algorithms for finding sparse solutions to ill-posed inverse problems. The models comprise typically a conditionally Gaussian prior model for the unknown, augmented by…

Numerical Analysis · Mathematics 2023-03-31 Daniela Calvetti , Erkki Somersalo

Well-spread samples are desirable in many disciplines because they improve estimation when target variables exhibit spatial structure. This paper introduces an integrated methodological framework for spreading samples over the population's…

Methodology · Statistics 2025-10-29 Bardia Panahbehagh , Mehdi Mohebbi , Amir Mohammad HosseiniNasab

One important source of systematics in galaxy redshift surveys comes from the estimation of the galaxy window function. Up until now, the impact of the uncertainty in estimating the galaxy window function on parameter inference has not been…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-02 Tanveer Karim , Mehdi Rezaie , Sukhdeep Singh , Daniel Eisenstein

We study the sources of biases and systematics in the derivation of galaxy properties of observational studies, focusing on stellar masses, star formation rates, gas/stellar metallicities, stellar ages and magnitudes/colors. We use…

Astrophysics of Galaxies · Physics 2015-10-16 Giovanni Guidi , Cecilia Scannapieco , C. Jakob Walcher

The halo-galaxy lensing correlation function or the average tangential shear profile over sampled halos is a very powerful means of measuring the halo masses, the mass profile, and the halo-mass correlation function of very large…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-13 Roland de Putter , Masahiro Takada

Bayesian sampling is an important task in statistics and machine learning. Over the past decade, many ensemble-type sampling methods have been proposed. In contrast to the classical Markov chain Monte Carlo methods, these new methods deploy…

Numerical Analysis · Mathematics 2024-05-14 Shi Chen , Zhiyan Ding , Qin Li

Randomly sampling points on surfaces is an essential operation in geometry processing. This sampling is computationally straightforward on explicit meshes, but it is much more difficult on other shape representations, such as widely-used…

Graphics · Computer Science 2025-06-16 Selena Ling , Abhishek Madan , Nicholas Sharp , Alec Jacobson

Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy's scale dark matter halos with galaxy-galaxy lensing techniques:…

Astrophysics · Physics 2007-05-23 M. Limousin , J-P. Kneib , P. Natarajan

We consider an alternative to conventional three-point statistics such as the bispectrum, which is purely based on the Fourier phases of the density field: the line correlation function. This statistic directly probes the non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Alexander Eggemeier , Robert E. Smith

We discuss cosmological inference from galaxy surveys at low and high redshifts. Studies of optical and IRAS redshift surveys with median redshift ${\bar z} \sim 0.02$ yield measurements of the density parameter $\Omega$ and the…

Astrophysics · Physics 2007-05-23 Ofer Lahav

Weak gravitational lensing is one of the key probes of cosmology. Cosmic shear surveys aimed at measuring the distribution of matter in the universe are currently being carried out (Pan-STARRS) or planned for the coming decade (DES, LSST,…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-22 Alberto Vallinotto

Not only source catalogs are extracted from astronomy observations. Their sky coverage is always carefully recorded and used in statistical analyses, such as correlation and luminosity function studies. Here we present a novel method for…

Instrumentation and Methods for Astrophysics · Physics 2014-03-20 Dongwei Fan , Tamás Budavári , Alexander S. Szalay , Chenzhou Cui , Yongheng Zhao

In the first paper of this series, we studied the effect of baryon acoustic oscillations (BAO), redshift space distortions (RSD) and weak lensing (WL) on measurements of angular cross-correlations in narrow redshift bins. Paper-II presented…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-09 Martin Eriksen , Enrique Gaztanaga

One of the fundamental tasks of science is to find explainable relationships between observed phenomena. One approach to this task that has received attention in recent years is based on probabilistic graphical modelling with sparsity…

Machine Learning · Statistics 2014-04-16 Peter Orchard , Felix Agakov , Amos Storkey

Many classification approaches first represent a test sample using the training samples of all the classes. This collaborative representation is then used to label the test sample. It was a common belief that sparseness of the…

Computer Vision and Pattern Recognition · Computer Science 2015-12-01 Naveed Akhtar , Faisal Shafait , Ajmal Mian

Photometric galaxy surveys probe the late-time Universe where the density field is highly non-Gaussian. A consequence is the emergence of the super-sample covariance (SSC), a non-Gaussian covariance term that is sensitive to fluctuations on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 S. Gouyou Beauchamps , F. Lacasa , I. Tutusaus , M. Aubert , P. Baratta , A. Gorce , Z. Sakr

Sparse neural networks have shown similar or better generalization performance than their dense counterparts while having higher parameter efficiency. This has motivated a number of works to learn or search for high performing sparse…

Machine Learning · Computer Science 2024-03-15 Rezsa Farahani
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