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The unknown intrinsic shape of source galaxies is one of the largest uncertainties of weak gravitational lensing (WL). It results in the so-called shape noise at the level of $\sigma_\epsilon^{\mathrm{WL}} \approx 0.26$, whereas the shear…

Astrophysics of Galaxies · Physics 2023-08-02 Pranjal R. S. , Elisabeth Krause , Hung-Jin Huang , Eric Huff , Jiachuan Xu , Tim Eifler , Spencer Everett

Level-set optimization formulations with data-driven constraints minimize a regularization functional subject to matching observations to a given error level. These formulations are widely used, particularly for matrix completion and…

Optimization and Control · Mathematics 2020-01-08 Robert Baraldi , Rajiv Kumar , Aleksandr Aravkin

We propose a new technique to measure the time delay of radio-loud gravitational lens systems, which does not rely on the excessive use of interferometric observations. Instead, the method is based on single-dish flux density monitoring of…

Astrophysics · Physics 2015-06-24 Bernhard Geiger , Peter Schneider

We present a new approach to gravitational lens massmap reconstruction. Our massmap solutions perfectly reproduce the positions, fluxes, and shears of all multiple images. And each massmap accurately recovers the underlying mass…

Astrophysics · Physics 2009-11-13 D. Coe , E. Fuselier , N. Benitez , T. Broadhurst , B. Frye , H. Ford

We consider simultaneously identifying the membership and locations of point sources that are convolved with different band-limited point spread functions, from the observation of their superpositions. This problem arises in…

Information Theory · Computer Science 2017-03-22 Yuanxin Li , Yuejie Chi

Gravitational lensing allows us to probe the structure of matter on a broad range of astronomical scales, and as light from a distant source traverses an intervening galaxy, compact matter such as planets, stars, and black holes act as…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-09 Hugh Garsden , Geraint F. Lewis

Modeling of microlensing events poses computational challenges for the resolution of the lens equation and the high dimensionality of the parameter space. In particular, numerical noise represents a severe limitation to fast and efficient…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 V. Bozza , V. Saggese , G. Covone , P. Rota , J. Zhang

When taking images against strong light sources, the resulting images often contain heterogeneous flare artifacts. These artifacts can importantly affect image visual quality and downstream computer vision tasks. While collecting real data…

Image and Video Processing · Electrical Eng. & Systems 2023-09-01 Yuyan Zhou , Dong Liang , Songcan Chen , Sheng-Jun Huang , Shuo Yang , Chongyi Li

Kernel based regularized interpolation is a well known technique to approximate a continuous multivariate function using a set of scattered data points and the corresponding function evaluations, or data values. This method has some…

Numerical Analysis · Mathematics 2018-07-26 Gabriele Santin , Dominik Wittwar , Bernard Haasdonk

Given a single image of a target object, image-to-3D generation aims to reconstruct its texture and geometric shape. Recent methods often utilize intermediate media, such as multi-view images or videos, to bridge the gap between input image…

Computer Vision and Pattern Recognition · Computer Science 2024-12-02 Jiacheng Wang , Zhedong Zheng , Wei Xu , Ping Liu

The observables in a strong gravitational lens are usually just the image positions and sometimes the flux ratios. We develop a new and simple algorithm which allows a set of models to be fitted exactly to the observations. Taking our cue…

Astrophysics · Physics 2008-11-26 N. W. Evans , H. J. Witt

Reconstructing the unknown spectrum of a given X-ray source is a common problem in a wide range of X-ray imaging tasks. For high-energy sources, transmission measurements are mostly used to recover the X-ray spectrum, as a solution to an…

Applied Physics · Physics 2023-07-13 Arthur Walker , Alexandre Friou , Kevin Ginsburger

We have developed a new software tool, Lensview, for modelling resolved gravitational lens images. Based on the LensMEM algorithm, the software finds the best fitting lens mass model and source brightness distribution using a maximum…

Astrophysics · Physics 2009-11-11 Randall B. Wayth , Rachel L. Webster

This work deals with a regularization method enforcing solution sparsity of linear ill-posed problems by appropriate discretization in the image space. Namely, we formulate the so called least error method in an $\ell^1$ setting and perform…

Numerical Analysis · Mathematics 2016-08-03 Kristian Bredies , Barbara Kaltenbacher , Elena Resmerita

In the coming years, strong gravitational lens discoveries are expected to increase in frequency by two orders of magnitude. Lens-modelling techniques are being developed to prepare for the coming massive influx of new lens data, and blind…

Astrophysics of Galaxies · Physics 2020-06-18 Philipp Denzel , Sampath Mukherjee , Jonathan P. Coles , Prasenjit Saha

Robust modelling of strong lensing systems is fundamental to exploit the information they contain about the distribution of matter in galaxies and clusters. In this work, we present Lensed, a new code which performs forward parametric…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-15 Nicolas Tessore , Fabio Bellagamba , R. Benton Metcalf

There remains an important need for the development of image reconstruction methods that can produce diagnostically useful images from undersampled measurements. In magnetic resonance imaging (MRI), for example, such methods can facilitate…

Image and Video Processing · Electrical Eng. & Systems 2021-06-28 Varun A. Kelkar , Sayantan Bhadra , Mark A. Anastasio

Kinematic weak lensing describes the distortion of a galaxy's projected velocity field due to lensing shear, an effect recently reported for the first time by Gurri et al. based on a sample of 18 galaxies at $z \sim 0.1$. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 Brian DiGiorgio , Kevin Bundy , Kyle B. Westfall , Alexie Leauthaud , David Stark

Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty…

Astrophysics · Physics 2009-11-13 Martin C. Smith , Przemyslaw Wozniak , Shude Mao , Takahiro Sumi

Gravitational lensing by clusters of galaxies offers a powerful probe of their structure and mass distribution. Deriving a lens magnification map for a galaxy cluster is a classic inversion problem and many methods have been developed over…

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