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Related papers: Fast simulations of extragalactic microlensing

200 papers

At any instant, there are roughly 1000 ongoing microlensing events to sources brighter than 20th magnitude in the Milky Way Galaxy. Large-scale maps of the microlensing optical depth and the mean timescale are constructed for a number of…

Astrophysics · Physics 2009-11-07 N. W. Evans , V. Belokurov

We study microlensing of the faint images that form close to the centers of strong gravitational lens galaxies. These central images, which have finally begun to yield to observations, naturally appear in dense stellar fields and may be…

Astrophysics · Physics 2008-11-26 Gregory Dobler , Charles R. Keeton , Joachim Wambsganss

We propose a new mass-mapping algorithm, specifically designed to recover small-scale information from a combination of gravitational shear and flexion. Including flexion allows us to supplement the shear on small scales in order to…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Francois Lanusse , Jean-Luc Starck , Adrienne Leonard , Sandrine Pires

The bilateral filter is a versatile non-linear filter that has found diverse applications in image processing, computer vision, computer graphics, and computational photography. A widely-used form of the filter is the Gaussian bilateral…

Computer Vision and Pattern Recognition · Computer Science 2016-11-15 Kunal N. Chaudhury

Scanning Electron Microscopy (SEM) is pivotal in revealing intricate micro- and nanoscale features across various research fields. However, obtaining high-resolution SEM images presents challenges, including prolonged scanning durations and…

Image and Video Processing · Electrical Eng. & Systems 2024-10-08 Tom Reclik , Setareh Medghalchi , Philipp Schumacher , Maximilian Wollenweber , Talal Al-Samman , Sandra Korte-Kerzel , Ulrich Kerzel

We present a fast Gauss transform in one dimension using nearly optimal sum-of-exponentials approximations of the Gaussian kernel. For up to about ten-digit accuracy, the approximations are obtained via best rational approximations of the…

Numerical Analysis · Mathematics 2019-09-24 Shidong Jiang

Strong-lensing images provide a wealth of information both about the magnified source and about the dark matter distribution in the lens. Precision analyses of these images can be used to constrain the nature of dark matter. However, this…

Instrumentation and Methods for Astrophysics · Physics 2022-05-25 Konstantin Karchev , Adam Coogan , Christoph Weniger

We present MADLens a python package for producing non-Gaussian lensing convergence maps at arbitrary source redshifts with unprecedented precision. MADLens is designed to achieve high accuracy while keeping computational costs as low as…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-18 Vanessa Böhm , Yu Feng , Max E. Lee , Biwei Dai

3D printing allows rapid fabrication of complex objects from digital designs. One 3D-printing process, direct laser writing, polymerises a light-sensitive material by steering a focused laser beam through the shape of the object to be…

We propose a new generative model of projected cosmic mass density maps inferred from weak gravitational lensing observations of distant galaxies (weak lensing mass maps). We construct the model based on a neural style transfer so that it…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-24 Masato Shirasaki , Shiro Ikeda

Lensless imaging is an elegant approach to high-resolution microscopy, which is rapidly gaining popularity in applications where imaging optics are problematic. However, current lensless imaging methods require objects to be placed within a…

The extended source effect on microlensing magnification is non-negligible and must be taken into account for in an analysis of microlensing. However, the evaluation of the extended source magnification is numerically expensive because it…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 Sunao Sugiyama

We apply a mass reconstruction technique to simulated large-scale structure gravitational distortion maps, from 2.5' to 10 degree scales, for different cosmological scenarii. The projected mass is reconstructed using a non-parametric least…

Astrophysics · Physics 2007-05-23 L. Van Waerbeke , F. Bernardeau , Y. Mellier

We present a code to generate mock observations of 21 cm intensity mapping experiments. The emphasis of the code is on reducing the computational cost of running a full-blown simulation, trading computational time for accuracy. The code can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 David Alonso , Pedro G. Ferreira , Mario G. Santos

Two new algorithms are described for matching two dimensional coordinate lists of point sources that are signifcantly faster than previous methods. By matching rarely occurring triangles (or more complex shapes) in the two lists, and by…

Astrophysics · Physics 2009-11-13 V. Tabur

Partitioning an image into superpixels based on the similarity of pixels with respect to features such as colour or spatial location can significantly reduce data complexity and improve subsequent image processing tasks. Initial algorithms…

Computer Vision and Pattern Recognition · Computer Science 2022-11-30 Jakob Geusen , Gustav Bredell , Tianfei Zhou , Ender Konukoglu

Hundreds of gravitational microlensing events have now been detected towards the Galactic bulge, with many more to come. The detection of fine structure in these events has been theorized to be an excellent way to discover extra-solar…

Astrophysics · Physics 2010-04-06 Kim Griest , Neda Safizadeh

We propose a scheme for imaging periodic surfaces using a superlens. By employing an inverse scattering model and the transformed field expansion method, we derive an approximate reconstruction formula for the surface profile, assuming…

Numerical Analysis · Mathematics 2024-03-05 Peijun Li , Yuliang Wang

We propose a deconvolution algorithm for images blurred and degraded by a Poisson noise. The algorithm uses a fast proximal backward-forward splitting iteration. This iteration minimizes an energy which combines a \textit{non-linear} data…

Applications · Statistics 2008-12-18 François-Xavier Dupé , Jalal Fadili , Jean Luc Starck

Existing fast algorithms for bilateral and nonlocal means filtering mostly work with grayscale images. They cannot easily be extended to high-dimensional data such as color and hyperspectral images, patch-based data, flow-fields, etc. In…

Computer Vision and Pattern Recognition · Computer Science 2018-11-07 Pravin Nair , Kunal. N. Chaudhury