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Cosmological gravitational microlensing is a useful technique for understanding the structure of the inner parts of a quasar, especially the accretion disk and the central supermassive black hole. So far, most of the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Georgios Vernardos , Christopher J. Fluke

Since the first observation of triple-lens gravitational microlensing in 2006, analyses of six more events have been published by the end of 2018. In three events the lens was a star with two planets; four involved a binary star with a…

Earth and Planetary Astrophysics · Physics 2019-07-30 Kamil Danek , David Heyrovsky

One of the main problems in the study of system of equations of the gravitational lens, is the computation of coordinates from the known position of the source. In the process of computing finds the solution of equations with two unknowns.…

General Relativity and Quantum Cosmology · Physics 2018-09-28 Albert Kotvytskiy , Semen Bronza , Svatoslav Vovk

We present a survey of the cosmological applications of the next generation of weak lensing surveys, paying special attention to the computational challenges presented by the number of galaxies, $N_{gal} ~$ 10$^{5}$. We focus on optimal…

Astrophysics · Physics 2009-11-07 N. Padmanabhan , U. Seljak , U. L. Pen

We propose a penalized likelihood framework for estimating multiple precision matrices from different classes. Most existing methods either incorporate no information on relationships between the precision matrices, or require this…

Machine Learning · Statistics 2020-03-03 Bradley S. Price , Aaron J. Molstad , Ben Sherwood

Accurately estimating the pose of an object is a crucial task in computer vision and robotics. There are two main deep learning approaches for this: geometric representation regression and iterative refinement. However, these methods have…

Computer Vision and Pattern Recognition · Computer Science 2024-01-30 Jaewoo Park , Jaeguk Kim , Nam Ik Cho

Gravitational lens modeling of spatially resolved sources is a challenging inverse problem with many observational constraints and model parameters. We examine established pixel-based source reconstruction algorithms for de-lensing the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Amitpal Tagore , Charles Keeton

Most existing approaches address multi-view subspace clustering problem by constructing the affinity matrix on each view separately and afterwards propose how to extend spectral clustering algorithm to handle multi-view data. This paper…

Computer Vision and Pattern Recognition · Computer Science 2017-08-30 Maria Brbic , Ivica Kopriva

We consider the problem of minimizing a sum of several convex non-smooth functions. We introduce a new algorithm called the selective linearization method, which iteratively linearizes all but one of the functions and employs simple…

Optimization and Control · Mathematics 2016-08-16 Yu Du , Xiaodong Lin , Andrzej Ruszczynski

We have developed a perturbative approach to microlensing due to an extrasolar planetary lens. In particular, we have found analytic formulae for triple images. We have used the formulae to investigate the astrometric microlensing due to…

Astrophysics · Physics 2009-11-07 Hideki Asada

We study a class of nonconvex nonsmooth optimization problems in which the objective is a sum of two functions: One function is the average of a large number of differentiable functions, while the other function is proper, lower…

Optimization and Control · Mathematics 2023-05-12 Duy-Nhat Phan , Sedi Bartz , Nilabja Guha , Hung M. Phan

We present the results of weak gravitational lensing statistics in four different cosmological $N$-body simulations. The data has been generated using an algorithm for the three-dimensional shear, which makes use of a variable softening…

Astrophysics · Physics 2009-10-31 Andrew J. Barber , Peter A. Thomas , H. M. P. Couchman , C. J. Fluke

Algorithms for robotic visual search can benefit from the use of visual attention methods in order to reduce computational costs. Here, we describe how three distinct mechanisms of visual attention can be integrated and productively used to…

Computer Vision and Pattern Recognition · Computer Science 2018-05-31 Amir Rasouli , John K. Tsotsos

Recovering high-fidelity images of the night sky from blurred observations is a fundamental problem in astronomy, where traditional methods typically fall short. In ground-based astronomy, combining multiple exposures to enhance…

Instrumentation and Methods for Astrophysics · Physics 2025-09-04 Yashil Sukurdeep , Fausto Navarro , Tamás Budavári

Wave effects in lensing form a rich phenomenon at the intersection of classical caustic singularities and quantum interference, yet are notoriously difficult to model. A large number of recently observed pulsars and fast radio bursts in…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-01 Job Feldbrugge

The increased sensitivity of future radio telescopes will result in requirements for higher dynamic range within the image as well as better resolution and immunity to interference. In this paper we propose a new matrix formulation of the…

Astrophysics · Physics 2014-11-18 Chen Ben-David , Amir Leshem

In recent years, various subspace algorithms have been developed to handle large-scale optimization problems. Although existing subspace Newton methods require fewer iterations to converge in practice, the matrix operations and full…

Optimization and Control · Mathematics 2024-06-05 Taisei Miyaishi , Ryota Nozawa , Pierre-Louis Poirion , Akiko Takeda

General purpose optimization techniques can be used to solve many problems in engineering computations, although their cost is often prohibitive when the number of degrees of freedom is very large. We describe a multilevel approach to speed…

Optimization and Control · Mathematics 2022-07-26 Rosa Donat , Sergio López Ureña

(abridged) Aims: RXS J113155.4-123155 (z=0.66) is a quadruply imaged lensed quasar with a resolved Einstein Ring. The goal of this paper is to provide a full characterization of this system, and more particularly accurate astrometry and…

Collaborative multi-robot perception provides multiple views of an environment, offering varying perspectives to collaboratively understand the environment even when individual robots have poor points of view or when occlusions are caused…

Robotics · Computer Science 2021-03-09 Brian Reily , Hao Zhang