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Control rate regression is a diffuse approach to account for heterogeneity among studies in meta-analysis by including information about the outcome risk of patients in the control condition. Correcting for the presence of measurement error…

Methodology · Statistics 2018-03-29 Annamaria Guolo

WL measurements have well-known shear estimation biases, which can be partially corrected for with the use of image simulations. We present an analysis of simulated images that mimic HST/ACS observations of high-redshift galaxy clusters,…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-26 B. Hernandez-Martin , T. Schrabback , H. Hoekstra , N. Martinet , J. Hlavacek-Larrondo , L. E. Bleem , M. D. Gladders , B. Stalder , A. A. Stark , M. Bayliss

The aperture photometry method is a powerful tool that enables us to study large star cluster systems efficiently. However, its accuracy depends on various factors, including the stochasticity of the stellar initial mass function and…

Astrophysics of Galaxies · Physics 2025-07-23 Karolis Daugevičius , Rima Stonkutė , Eimantas Kriščiūnas , Erikas Cicėnas , Vladas Vansevičius

The bias in the determination of the Hubble parameter and the Hubble constant in the modern Universe is discussed. It could appear due to statistical processing of data on galaxies redshifts and estimated distances based on some statistical…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-22 S. L. Parnovsky

Recent investigations in noise contrastive estimation suggest, both empirically as well as theoretically, that while having more "negative samples" in the contrastive loss improves downstream classification performance initially, beyond a…

Machine Learning · Computer Science 2022-06-24 Pranjal Awasthi , Nishanth Dikkala , Pritish Kamath

In this work, image analysis techniques used in astrophysics to detect low-contrast signals have been adapted in the processing of Computed Tomography (CT) images, combining Centroidal Voronoi Tessellation (CVT) and machine learning…

Medical Physics · Physics 2025-03-11 Lorenzo Lasagni

Although many exoplanets have been indirectly detected over the last years, direct imaging of them with ground-based telescopes remains challenging. In the presence of atmospheric fluctuations, it is ambitious to resolve the high brightness…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Jakob Roth , Gianluca Li Causi , Vincenzo Testa , Philipp Arras , Torsten A. Enßlin

Super-sample covariance (SSC) is the dominant source of statistical error on large scale structure (LSS) observables for both current and future galaxy surveys. In this work, we concentrate on the SSC of cluster counts, also known as sample…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-06 Fabien Lacasa , Marcos Lima , Michel Aguena

Contrastive learning (CL) methods effectively learn data representations in a self-supervision manner, where the encoder contrasts each positive sample over multiple negative samples via a one-vs-many softmax cross-entropy loss. By…

Machine Learning · Computer Science 2023-08-16 Huangjie Zheng , Xu Chen , Jiangchao Yao , Hongxia Yang , Chunyuan Li , Ya Zhang , Hao Zhang , Ivor Tsang , Jingren Zhou , Mingyuan Zhou

We investigate the abundance, small-scale clustering and galaxy-galaxy lensing signal of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS). To this end, we present new measurements of the redshift and stellar mass dependence of…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-07 Johannes U. Lange , Xiaohu Yang , Hong Guo , Wentao Luo , Frank C. van den Bosch

The statistical analysis of cosmic large-scale structure is most often based on simple two-point summary statistics, like the power spectrum or the two-point correlation function of a sample of galaxies or other types of tracers. In…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-23 Eniko Regos , Volker Springel , Sownak Bose , Boryana Hadzhiyska , Cesar Hernandez-Aguayo

Intrinsic alignments between galaxies and the large-scale structure contaminate galaxy clustering analyses and impact constraints on galaxy bias and the growth rate of structure in the Universe. This is the result of alignments inducing a…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-31 Karel Zwetsloot , Nora Elisa Chisari

Every halo finding algorithm must make a critical yet relatively arbitrary choice: it must decide which structures are parent halos, and which structures are sub-halos of larger halos. We refer to this choice as ${\it percolation}$. We…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Rafael Garcia , Eduardo Rozo

Contrastive Learning (CL) has been successfully applied to classification and other downstream tasks related to concrete concepts, such as objects contained in the ImageNet dataset. No attempts seem to have been made so far in applying this…

Machine Learning · Computer Science 2025-05-30 Daniel N. Nissani

Modern astronomy has been rapidly increasing our ability to see deeper into the universe, acquiring enormous samples of cosmic populations. Gaining astrophysical insights from these datasets requires a wide range of sophisticated…

Instrumentation and Methods for Astrophysics · Physics 2020-12-11 Eric D. Feigelson , Rafael S. de Souza , Emille E. O. Ishida , Gutti Jogesh Babu

Strong gravitational lensing by galaxy clusters is a fundamental tool to study dark matter and constrain the geometry of the Universe. Recently, the Hubble Space Telescope Frontier Fields programme has allowed a significant improvement of…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-19 Ana Acebron , Eric Jullo , Marceau Limousin , André Tilquin , Carlo Giocoli , Mathilde Jauzac , Guillaume Mahler , Johan Richard

The next generation of large sky photometric surveys will finally be able to use arc statistics as a cosmological probe. Here we present the first of a series of papers on this topic. In particular, we study how arc counts are sensitive to…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Michele Boldrin , Carlo Giocoli , Massimo Meneghetti , Lauro Moscardini , Giuseppe Tormen , Andrea Biviano

We derive contrast measures which involve the number of looks and the complex correlation coefficient between polarization channels in PolSAR imagery. Using asymptotic results which characterize the behavior of these measures, we derive…

Statistics Theory · Mathematics 2014-02-11 Alejandro C. Frery , Renato J. Cintra , Abraão D. C. Nascimento

Relativistic effects in clustering observations have been shown to introduce scale-dependent corrections to the galaxy over-density field on large scales, which may hamper the detection of primordial non-Gaussianity $f_\textrm{NL}$ through…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Mike Shengbo Wang , Florian Beutler , David Bacon

Faint red galaxies in the Sloan Digital Sky Survey show a puzzling clustering pattern in previous measurements. In the two-point correlation function (2PCF), they appear to be strongly clustered on small-scales, indicating a tendency to…

Astrophysics of Galaxies · Physics 2016-06-06 Haojie Xu , Zheng Zheng , Hong Guo , Ju Zhu , Idit Zehavi