Generative modelling for mass-mapping with fast uncertainty quantification

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Bibliographic Details
Title: Generative modelling for mass-mapping with fast uncertainty quantification
Authors: Jessica J Whitney, Tobías I Liaudat, Matthew A Price, Matthijs Mars, Jason D McEwen
Contributors: HEP, INSPIRE
Source: Monthly Notices of the Royal Astronomical Society. 542:2464-2479
Publication Status: Preprint
Publisher Information: Oxford University Press (OUP), 2025.
Publication Year: 2025
Subject Terms: Cosmology and Nongalactic Astrophysics (astro-ph.CO), [PHYS.PHYS.PHYS-INS-DET] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation and Methods for Astrophysics, FOS: Physical sciences, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], Cosmology and Nongalactic Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Description: Understanding the nature of dark matter in the Universe is an important goal of modern cosmology. A key method for probing this distribution is via weak gravitational lensing mass-mapping – a challenging ill-posed inverse problem where one infers the convergence field from observed shear measurements. Upcoming stage IV surveys, such as those made by the Vera C. Rubin Observatory and Euclid satellite, will provide a greater quantity and precision of data for lensing analyses, necessitating high-fidelity mass-mapping methods that are computationally efficient and that also provide uncertainties for integration into downstream cosmological analyses. In this work we introduce a novel generative adversarial network (GAN) for mass-mapping, which we call the Mass-Mapping GAN (MMGAN), based on a regularized conditional GAN framework, which generates approximate posterior samples of the convergence field given shear data. We adopt Wasserstein GANs to improve training stability and apply regularization techniques to overcome mode collapse, issues that otherwise are particularly acute for conditional GANs. We train and validate our model on a mock data set modeled after the Cosmic Evolution Survey (COSMOS) before applying it to true COSMOS data. Our approach significantly outperforms the Kaiser–Squires technique and achieves similar reconstruction fidelity as alternative state-of-the-art deep learning approaches. Notably, while alternative approaches for generating samples from a learned posterior are slow (e.g. requiring $\sim$10 GPU min per posterior sample), MMGAN can produce a high-quality convergence sample in less than a second.
Document Type: Article
Language: English
ISSN: 1365-2966
0035-8711
DOI: 10.1093/mnras/staf1356
DOI: 10.48550/arxiv.2410.24197
Access URL: http://arxiv.org/abs/2410.24197
Rights: CC BY
Accession Number: edsair.doi.dedup.....ff3f6f78e1d9911a317ae3094c2e0cb6
Database: OpenAIRE
Description
Abstract:Understanding the nature of dark matter in the Universe is an important goal of modern cosmology. A key method for probing this distribution is via weak gravitational lensing mass-mapping – a challenging ill-posed inverse problem where one infers the convergence field from observed shear measurements. Upcoming stage IV surveys, such as those made by the Vera C. Rubin Observatory and Euclid satellite, will provide a greater quantity and precision of data for lensing analyses, necessitating high-fidelity mass-mapping methods that are computationally efficient and that also provide uncertainties for integration into downstream cosmological analyses. In this work we introduce a novel generative adversarial network (GAN) for mass-mapping, which we call the Mass-Mapping GAN (MMGAN), based on a regularized conditional GAN framework, which generates approximate posterior samples of the convergence field given shear data. We adopt Wasserstein GANs to improve training stability and apply regularization techniques to overcome mode collapse, issues that otherwise are particularly acute for conditional GANs. We train and validate our model on a mock data set modeled after the Cosmic Evolution Survey (COSMOS) before applying it to true COSMOS data. Our approach significantly outperforms the Kaiser–Squires technique and achieves similar reconstruction fidelity as alternative state-of-the-art deep learning approaches. Notably, while alternative approaches for generating samples from a learned posterior are slow (e.g. requiring $\sim$10 GPU min per posterior sample), MMGAN can produce a high-quality convergence sample in less than a second.
ISSN:13652966
00358711
DOI:10.1093/mnras/staf1356