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Weak lensing mass-mapping is a useful tool to access the full distribution of dark matter on the sky, but because of intrinsic galaxy ellipticies and finite fields/missing data, the recovery of dark matter maps constitutes a challenging…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Benjamin Remy , Francois Lanusse , Niall Jeffrey , Jia Liu , Jean-Luc Starck , Ken Osato , Tim Schrabback

Computing the marginal likelihood or evidence is one of the core challenges in Bayesian analysis. While there are many established methods for estimating this quantity, they predominantly rely on using a large number of posterior samples…

Computation · Statistics 2021-02-26 Eric Chuu , Debdeep Pati , Anirban Bhattacharya

We present a novel framework for jointly modelling the weak lensing source galaxy redshift distribution and the intrinsic alignment of galaxies via a shared luminosity function (LF). Considering this framework within the context of a Rubin…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-13 Nikolina Šarčević , C. Danielle Leonard , Markus M. Rau , LSST Dark Energy Science Collaboration

The interpretation of cosmological observables requires the use of increasingly sophisticated theoretical models. Since these models are becoming computationally very expensive and display non-trivial uncertainties, the use of standard…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Marcos Pellejero-Ibañez , Raul E. Angulo , Giovanni Aricó , Matteo Zennaro , Sergio Contreras , Jens Stücker

Cosmological constraints using weak gravitational lensing measurements from the Roman Space Telescope will require a powerful method for modelling uncertainties in the galaxy redshift distribution. In this work, we use an optimized version…

We apply Markov Chain Monte Carlo (MCMC) to the problem of parametric galaxy modeling, estimating posterior distributions of galaxy properties such as ellipticity and brightness for more than 100,000 images of galaxies taken from DC2, a…

Instrumentation and Methods for Astrophysics · Physics 2023-09-20 James J. Buchanan , Michael D. Schneider , Kerianne Pruett , Robert E. Armstrong

To measure the mass of foreground objects with weak gravitational lensing, one needs to estimate the redshift distribution of lensed background sources. This is commonly done in an empirical fashion, i.e. with a reference sample of galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Daniel Gruen , Fabrice Brimioulle

Segmenting images of low quality or with missing data is a challenging problem. Integrating statistical prior information about the shapes to be segmented can improve the segmentation results significantly. Most shape-based segmentation…

Computer Vision and Pattern Recognition · Computer Science 2016-11-14 Ertunc Erdil , Sinan Yıldırım , Müjdat Çetin , Tolga Taşdizen

We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the CFHTLenS weak lensing survey - the first application of this method to data. In the first approach, we sample…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 Justin Alsing , Alan F. Heavens , Andrew H. Jaffe

We present a novel Bayesian inference tool that uses a neural network to parameterise efficient Markov Chain Monte-Carlo (MCMC) proposals. The target distribution is first transformed into a diagonal, unit variance Gaussian by a series of…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-03 Adam Moss

The accumulation of redshifts provides a significant observational bottleneck when using galaxy cluster surveys to constrain cosmological parameters. We propose a simple method to allow the use of samples where there is a fraction of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 A. Bonaldi , R. A. Battye , M. L. Brown

Convolutional neural network (CNN) has achieved unprecedented success in image super-resolution tasks in recent years. However, the network's performance depends on the distribution of the training sets and degrades on out-of-distribution…

Computer Vision and Pattern Recognition · Computer Science 2021-05-20 Aupendu Kar , Prabir Kumar Biswas

We introduce a framework that enables efficient sampling from learned probability distributions for MRI reconstruction. Different from conventional deep learning-based MRI reconstruction techniques, samples are drawn from the posterior…

Machine Learning · Computer Science 2023-07-21 Guanxiong Luo , Moritz Blumenthal , Martin Heide , Martin Uecker

Markov chain Monte Carlo (MCMC) methods have not been broadly adopted in Bayesian neural networks (BNNs). This paper initially reviews the main challenges in sampling from the parameter posterior of a neural network via MCMC. Such…

Machine Learning · Statistics 2021-10-05 Theodore Papamarkou , Jacob Hinkle , M. Todd Young , David Womble

The statistics of peaks in weak lensing convergence maps is a promising tool to investigate both the properties of dark matter haloes and constrain the cosmological parameters. We study how the number of detectable peaks and its scaling…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 V. F. Cardone , S. Camera , M. Sereno , G. Covone , R. Maoli , R. Scaramella

Absorption line spectroscopy is a powerful way of measuring properties of stars and the interstellar medium. Absorption spectra are often analyzed manually, an approach that limits reproducibility and which cannot practically be applied to…

Instrumentation and Methods for Astrophysics · Physics 2020-01-29 Kirill Tchernyshyov

Constrained decoding enables Language Models (LMs) to produce samples that provably satisfy hard constraints. However, existing constrained-decoding approaches often distort the underlying model distribution, a limitation that is especially…

Artificial Intelligence · Computer Science 2025-06-09 Emmanuel Anaya Gonzalez , Sairam Vaidya , Kanghee Park , Ruyi Ji , Taylor Berg-Kirkpatrick , Loris D'Antoni

Weak gravitational lensing has become a common tool to constrain the cosmological model. The majority of the methods to derive constraints on cosmological parameters use second-order statistics of the cosmic shear. Despite their success,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Sandrine Pires , Adrienne Leonard , Jean-Luc Starck

The ratio of the average tangential shear signal of different weak lensing source populations around the same lens galaxies, also known as a shear ratio, provides an important test of lensing systematics and a potential source of…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-01 Ni Emas , Chris Blake , Rossana Ruggeri , Anna Porredon

Measurements of weak gravitational lensing using the cosmic microwave background and the shapes of galaxies have refined our understanding of the late-time history of the Universe. While optical surveys have been the primary source for…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Alba Kalaja , Ian Harrison , William R Coulton