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We introduce deep-field metacalibration, a new technique that reduces the pixel noise in metacalibration estimators of weak lensing shear signals by using a deeper imaging survey for calibration. In standard metacalibration, when estimating…

Instrumentation and Methods for Astrophysics · Physics 2023-05-19 Zhuoqi Zhang , Matthew R. Becker , Erin S. Sheldon

The magnification of galaxies in modern galaxy surveys induces additional correlations in the cosmic shear, galaxy-galaxy lensing and clustering observables used in modern lensing "3x2pt" analyses, due to sample selection. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Christopher A. J. Duncan , Joachim Harnois-Déraps , Lance Miller

We present and describe im3shape, a new publicly available galaxy shape measurement code for weak gravitational lensing shear. im3shape performs a maximum likelihood fit of a bulge-plus-disc galaxy model to noisy images, incorporating an…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Joe Zuntz , Tomasz Kacprzak , Lisa Voigt , Michael Hirsch , Barnaby Rowe , Sarah Bridle

One surprising trait of neural networks is the extent to which their connections can be pruned with little to no effect on accuracy. But when we cross a critical level of parameter sparsity, pruning any further leads to a sudden drop in…

Machine Learning · Computer Science 2023-01-20 Junyang Cai , Khai-Nguyen Nguyen , Nishant Shrestha , Aidan Good , Ruisen Tu , Xin Yu , Shandian Zhe , Thiago Serra

When measuring the roughness of rough surfaces, the limited sizes of scanned areas lead to its systematic underestimation. Levelling by polynomials and other filtering used in real-world processing of atomic force microscopy data increases…

Data Analysis, Statistics and Probability · Physics 2020-04-28 David Nečas , Petr Klapetek , Miroslav Valtr

The unprecedented amount and the excellent quality of lensing data that the upcoming ground- and space-based surveys will produce represent a great opportunity to shed light on the questions that still remain unanswered concerning our…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-27 Carolina Parroni , Edouard Tollet , Vincenzo F. Cardone , Roberto Maoli , Roberto Scaramella

The fairness of a deep neural network is strongly affected by dataset bias and spurious correlations, both of which are usually present in modern feature-rich and complex visual datasets. Due to the difficulty and variability of the task,…

Computer Vision and Pattern Recognition · Computer Science 2024-02-28 Rebecca S Stone , Nishant Ravikumar , Andrew J Bulpitt , David C Hogg

Recent results show that deep neural networks achieve excellent performance even when, during training, weights are quantized and projected to a binary representation. Here, we show that this is just the tip of the iceberg: these same…

Neural and Evolutionary Computing · Computer Science 2016-06-08 Paul Merolla , Rathinakumar Appuswamy , John Arthur , Steve K. Esser , Dharmendra Modha

We present a new method to constrain local primordial non-Gaussianity using the large-scale modulation of the local lensing power spectrum. Our work extends our recently proposed $\pi$-field method for primordial non-Gaussianity estimation…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-06 Shi-Hui Zang , Moritz Münchmeyer

We have developed a new technique for weak lensing analysis, with which the effect of the point spread function (PSF) on small galaxy images can be corrected for accurately. Rather than relying on weighted second moments of detected images,…

Astrophysics · Physics 2016-08-30 Konrad Kuijken

In this paper we address the challenge of extracting maps of spatially varying unknown additive biases from cosmic shear data. This is done by exploiting the isotropy of the cosmic shear field, and the anisotropy of a typical additive bias…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-21 T. D. Kitching , A. C. Deshpande , P. L. Taylor

A persistent challenge in astronomical machine learning is a systematic bias where predictions compress the dynamic range of true values-high values are consistently predicted too low while low values are predicted too high. Understanding…

Instrumentation and Methods for Astrophysics · Physics 2025-07-17 Yuan-Sen Ting

Feature selection is important step in machine learning since it has shown to improve prediction accuracy while depressing the curse of dimensionality of high dimensional data. The neural networks have experienced tremendous success in…

Machine Learning · Computer Science 2021-07-13 Peter Bugata , Peter Drotar

Spiking Neural Network (SNN), originating from the neural behavior in biology, has been recognized as one of the next-generation neural networks. Conventionally, SNNs can be obtained by converting from pre-trained Artificial Neural Networks…

Neural and Evolutionary Computing · Computer Science 2022-05-23 Yuhang Li , Shikuang Deng , Xin Dong , Shi Gu

The measurement of weak gravitational lensing is currently limited to a precision of ~10% by instabilities in galaxy shape measurement techniques and uncertainties in their calibration. The potential of large, on-going and future cosmic…

Astrophysics · Physics 2009-11-10 Richard Massey , Alexandre Refregier , David Bacon

We present new tests to identify stationary position-dependent additive shear biases in weak gravitational lensing data sets. These tests are important diagnostics for currently ongoing and planned cosmic shear surveys, as such biases…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-24 Edo van Uitert , Peter Schneider

Artificial intelligence (AI) models trained using medical images for clinical tasks often exhibit bias in the form of disparities in performance between subgroups. Since not all sources of biases in real-world medical imaging data are…

Computer Vision and Pattern Recognition · Computer Science 2024-07-02 Emma A. M. Stanley , Raissa Souza , Anthony Winder , Vedant Gulve , Kimberly Amador , Matthias Wilms , Nils D. Forkert

The uncertainty in the photometric redshift estimation is one of the major systematics in weak lensing cosmology. The self-calibration method is able to reduce this systematics without assuming strong priors. We improve the recently…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-07 Hui Peng , Haojie Xu , Le Zhang , Zhao Chen , Yu Yu

Large catalogs of shear-selected peaks have recently become a reality. In order to properly interpret the abundance and properties of these peaks, it is necessary to take into account the effects of the clustering of source galaxies, among…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Fabian Schmidt , Eduardo Rozo

The integrated shear 3-point correlation function $\zeta_{\pm}$ measures the correlation between the local shear 2-point function $\xi_{\pm}$ and the 1-point shear aperture mass in patches of the sky. Unlike other higher-order statistics,…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-17 Zhengyangguang Gong , Anik Halder , Alexandre Barreira , Stella Seitz , Oliver Friedrich