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We present a fast algorithm for generating full sky, high resolution ($\sim 5'$) simulations of the CMB anisotropy pattern. We also discuss the inverse problem, that of evaluating from such a map the full set of $a_{\ell m}$'s and the…

Astrophysics · Physics 2014-10-13 Pio Francesco Muciaccia , Paolo Natoli , Nicola Vittorio

A phase retrieval technique using a spatial light modulator (SLM) and a phase diffuser for a fast reconstruction of smooth wave fronts is demonstrated experimentally. Diffuse illumination of a smooth test object with the aid of a phase…

Optics · Physics 2015-06-11 Mostafa Agour , Percival F. Almoro , Claas Falldorf

Photomultiplier tubes (PMTs) are widely deployed at neutrino and dark matter experiments for photon counting. When multiple photons hit a PMT consecutively, their photo-electron (PE) pulses pile up to hinder the precise measurements of the…

High Energy Physics - Experiment · Physics 2025-09-12 Yuyi Wang , Aiqiang Zhang , Yiyang Wu , Benda Xu , Xuewei Liu , Jiajie Chen , Zhe Wang , Shaomin Chen

It is common practice in cosmology to model large-scale structure observables as lognormal random fields, and this approach has been successfully applied in the past to the matter density and weak lensing convergence fields separately. We…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-18 Henrique S. Xavier , Filipe B. Abdalla , Benjamin Joachimi

Strong gravitational lensing acts as a cosmic telescope, enabling the study of the high-redshift universe. Astronomical interferometers, such as the Atacama Large Millimeter/submillimeter Array (ALMA), have provided high-resolution images…

We present a ray tracing code to compute integrated cosmological observables on the fly in AMR N-body simulations. Unlike conventional ray tracing techniques, our code takes full advantage of the time and spatial resolution attained by the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-23 Alexandre Barreira , Claudio Llinares , Sownak Bose , Baojiu Li

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

Weak lensing by large-scale structure is an invaluable cosmological tool given that most of the energy density of the concordance cosmology is invisible. Several large ground-based imaging surveys will attempt to measure this effect over…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Eric M. Huff , Christopher M. Hirata , Rachel Mandelbaum , David Schlegel , Uros Seljak , Robert H. Lupton

The statistics of gravitational lensing can provide us with a very powerful probe of the mass distribution of matter in the universe. By comparing predicted strong lensing probabilities with observations, we can test the mass distribution…

Astrophysics · Physics 2009-11-10 Tong-Jie Zhang

Numerical simulation of atmospheric turbulence is one of the biggest bottlenecks in developing computational techniques for solving the inverse problem in long-range imaging. The classical split-step method is based upon numerical wave…

Image and Video Processing · Electrical Eng. & Systems 2022-10-14 Nicholas Chimitt , Xingguang Zhang , Zhiyuan Mao , Stanley H. Chan

In this paper we discuss propagation of the weak high-frequency gravitational waves in a curved spacetime background. We develop a so-called spinoptics approximation which takes into account interaction of the spin of the field with the…

General Relativity and Quantum Cosmology · Physics 2024-06-27 Valeri P. Frolov , Andrey A. Shoom

Omnidirectional images are increasingly used in robotics and vision due to their wide field of view. However, extending 3D Gaussian Splatting (3DGS) to panoramic camera models remains challenging, as existing formulations are designed for…

Computer Vision and Pattern Recognition · Computer Science 2026-03-10 Zhe Yang , Guoqiang Zhao , Sheng Wu , Kai Luo , Kailun Yang

We describe how gravitational lensing of fast radio bursts (FRBs) is affected by a plasma screen in the vicinity of the lens or somewhere between the source and the observer. Wave passage through a turbulent medium affects gravitational…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Pawan Kumar , Paz Beniamini

We present a simple modification of the direct-forcing immersed boundary method (IBM) proposed by Uhlmann [J. Comput. Phys, 2005] in order to enable it to be applied to particulate flows with solid-to-fluid density ratios around unity. The…

Fluid Dynamics · Physics 2023-06-21 Manuel Garcia-Villalba , Blanca Fuentes , Jan Dusek , Manuel Moriche , Markus Uhlmann

We introduce the method and the implementation of a cosmological simulation of a class of metric-variation f(R) models that accelerate the cosmological expansion without a cosmological constant and evade solar-system bounds of small-field…

Astrophysics · Physics 2008-12-30 Hiroaki Oyaizu

We continue our investigation of the optical properties of the solar gravitational lens (SGL). We treat the Sun as an extended axisymmetric body and model its gravitational field using zonal harmonics. We consider a point source that is…

General Relativity and Quantum Cosmology · Physics 2021-08-06 Slava G. Turyshev , Viktor T. Toth

In this paper we discuss a new method which can be used to obtain arbitrarily accurate analytical expressions for the deflection angle of light propagating in a given metric. Our method works by mapping the integral into a rapidly…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Paolo Amore , Santiago Arceo Diaz

Modeling the Point Spread Function (PSF) of wide-field surveys is vital for many astrophysical applications and cosmological probes including weak gravitational lensing. The PSF smears the image of any recorded object and therefore needs to…

Instrumentation and Methods for Astrophysics · Physics 2018-07-26 Jörg Herbel , Tomasz Kacprzak , Adam Amara , Alexandre Refregier , Aurelien Lucchi

In this paper, we develop and analyze a stochastic algorithm for solving space-time fractional diffusion models, which are widely used to describe anomalous diffusion dynamics. These models pose substantial numerical challenges due to the…

Numerical Analysis · Mathematics 2025-08-29 Tengteng Cui , Chengtao Sheng , Bihao Su , Zhi Zhou