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A new magnetically charged Kiselev black hole solution is used to study the null geodesics in this spacetime. We derive the equations of motion for the null geodesics and analyze their properties, including the gravitational lensing effect.…

General Relativity and Quantum Cosmology · Physics 2025-04-17 Vitalie Lungu

Schwarzschild black holes can produce strong gravitational lensing. The relativistic images are produced due to bending of light around the black hole. We propose a model equation to study the strong gravitational lensing. The model…

General Relativity and Quantum Cosmology · Physics 2012-08-17 Tushar Kanti Dey

Weak gravitational lensing is the slight distortion of galaxy shapes caused primarily by the gravitational effects of dark matter in the universe. In our work, we seek to invert the weak lensing signal from 2D telescope images to…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-22 Brandon Zhao , Aviad Levis , Liam Connor , Pratul P. Srinivasan , Katherine L. Bouman

Rendering moving human bodies at free viewpoints only from a monocular video is quite a challenging problem. The information is too sparse to model complicated human body structures and motions from both view and pose dimensions. Neural…

Computer Vision and Pattern Recognition · Computer Science 2023-03-28 Taoran Yi , Jiemin Fang , Xinggang Wang , Wenyu Liu

In this paper, the null geodesics and gravitational lensing in a nonsingular spacetime are investigated. According to the nature of the null geodesics, the spacetime is divided into several cases. In the weak deflection limit, we find the…

General Relativity and Quantum Cosmology · Physics 2015-10-12 Shao-Wen Wei , Yu-Xiao Liu , Chun-E Fu

Gravitational lensing is a powerful tool for constraining substructure in the mass distribution of galaxies, be it from the presence of dark matter sub-halos or due to physical mechanisms affecting the baryons throughout galaxy evolution.…

Astrophysics of Galaxies · Physics 2020-10-28 Georgios Vernardos , Grigorios Tsagkatakis , Yannis Pantazis

We present GeoNeRF, a generalizable photorealistic novel view synthesis method based on neural radiance fields. Our approach consists of two main stages: a geometry reasoner and a renderer. To render a novel view, the geometry reasoner…

Computer Vision and Pattern Recognition · Computer Science 2022-03-22 Mohammad Mahdi Johari , Yann Lepoittevin , François Fleuret

We consider a machine learning algorithm to detect and identify strong gravitational lenses on sky images. First, we simulate different artificial but very close to reality images of galaxies, stars and strong lenses, using six different…

Instrumentation and Methods for Astrophysics · Physics 2021-04-06 H. G. Khachatryan

While recent advancements in animatable human rendering have achieved remarkable results, they require test-time optimization for each subject which can be a significant limitation for real-world applications. To address this, we tackle the…

Computer Vision and Pattern Recognition · Computer Science 2024-04-23 Mana Masuda , Jinhyung Park , Shun Iwase , Rawal Khirodkar , Kris Kitani

We present recent developments on numerical algorithms for computing photon and particle trajectories in the surrounding of compact objects. Strong gravity around neutron stars or black holes causes relativistic effects on the motion of…

High Energy Astrophysical Phenomena · Physics 2020-04-08 Fabio Bacchini , Bart Ripperda , Lorenzo Sironi

We have developed a realistic, fully general relativistic computer code to simulate optical projection in a strong, spherically symmetric gravitational field. The standard theoretical analysis of optical projection for an observer in the…

Astrophysics · Physics 2009-11-13 P. Bakala , P. Cermak , S. Hledik , Z. Stuchlik , K. Truparova

We study gravitational lensing of neutrinos in a Kaluza-Klein black hole spacetime and compare the oscillation probabilities of neutrinos with the case of lensing by black holes in General Relativity. We show that measuring neutrino…

General Relativity and Quantum Cosmology · Physics 2023-08-17 Hrishikesh Chakrabarty , Auttakit Chatrabhuti , Daniele Malafarina , Bhuddhanubhap Silasan , Takol Tangphati

We provide new very simple and compact expressions for the efficient calculation of gravitational lens optical scalars for Kerr spacetime which are exact along any null geodesic. These new results are obtained recurring to well known…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-05 Ezequiel F. Boero , Osvaldo M. Moreschi

Measurements from the Event Horizon Telescope enabled the visualization of light emission around a black hole for the first time. So far, these measurements have been used to recover a 2D image under the assumption that the emission field…

Computer Vision and Pattern Recognition · Computer Science 2022-04-11 Aviad Levis , Pratul P. Srinivasan , Andrew A. Chael , Ren Ng , Katherine L. Bouman

Using a recently found black hole solution in the framework of the Poincar{\'e} gauge theory of gravity, we study gravitational lensing for a system where the lens is a static spherically symmetric black hole. By analyzing the equations of…

General Relativity and Quantum Cosmology · Physics 2021-10-19 Saboura Sadat Zamani , Siamak Akhshabi

We propose a simple yet effective neural network-based framework for global illumination rendering. Recently, rendering techniques that learn neural radiance caches by minimizing the difference (i.e., residual) between the left and right…

Computer Vision and Pattern Recognition · Computer Science 2024-10-15 In-Young Cho , Jaewoong Cho

Gravitational lensing directly measures mass density fluctuations along the lines of sight to very distant objects. No assumptions need to be made concerning bias, the ratio of fluctuations in galaxy density to mass density. Hence, lensing…

Astrophysics · Physics 2007-05-23 Joachim Wambsganss , Renyue Cen , Jeremiah P. Ostriker

Generative deep learning methods built upon Convolutional Neural Networks (CNNs) provide a great tool for predicting non-linear structure in cosmology. In this work we predict high resolution dark matter halos from large scale, low…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-25 David Schaurecker , Yin Li , Jeremy Tinker , Shirley Ho , Alexandre Refregier

Current X-ray observations and simulations show that gravitational lensing can be used to infer the structure near the event horizons of black holes, constrain the dynamics and evolution of black-hole accretion and outflows, test general…

High Energy Astrophysical Phenomena · Physics 2019-04-04 George Chartas , Henric Krawczynski , David Pooley , Richard F. Mushotzky , Andrew J. Ptak

Convolutional Neural Networks (ConvNets) are one of the most promising methods for identifying strong gravitational lens candidates in survey data. We present two ConvNet lens-finders which we have trained with a dataset composed of real…