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Gravitational lensing is a powerful concept in the Astrophysics to study black holes. The gravitational field of a massive object like a galaxy or black hole bends and magnifies the light from a distant object behind it. The Schwarzchild…

High Energy Physics - Phenomenology · Physics 2024-10-01 Amritansh Mehrotra , R. Kanishka

We demonstrate that microlensing can be used for detecting planets in binary stellar systems. This is possible because in the geometry of planetary binary systems where the planet orbits one of the binary component and the other binary star…

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

Scattering rigidity of a Riemannian manifold allows one to tell the metric of a manifold with boundary by looking at the directions of geodesics at the boundary. Lens rigidity allows one to tell the metric of a manifold with boundary from…

Differential Geometry · Mathematics 2015-08-12 Haomin Wen

If the Universe satisfies a perturbed Friedmann-Lema\^{\i}tre model, then the bright matter (e.g. radio-loud active galactic nuclei, RLAGNs) may be topologically lensed by global geometry. The generation of candidate topological lensing…

Astrophysics · Physics 2007-05-23 B. F. Roukema , A. Marecki , S. Bajtlik , R. E. Spencer

Direct observation of black holes is one of the grand challenges in astronomy. If there are super-compact objects which possess unstable circular orbits of photons, however, it may be difficult to distinguish them from black holes by…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Nobuyuki Sakai , Hiromi Saida , Takashi Tamaki

Background. Relative astrometry at or below the micro-arcsec level with a 1m class space telescope has been repeatedly proposed as a tool for exo-planet detection and characterization, as well as for several topics at the forefront of…

Instrumentation and Methods for Astrophysics · Physics 2022-12-07 Mario Gai , Alberto Vecchiato , Alberto Riva , Alexey Butkevich , Deborah Busonero , Zhaoxiang Qi , Mario Lattanzi

Astrophotonics is a burgeoning field that lies at the interface of photonics and modern astronomical instrumentation. Here we provide a pedagogical review of basic photonic functions that enable modern instruments, and give an overview of…

Instrumentation and Methods for Astrophysics · Physics 2024-04-04 Simon Charles Ellis , Joss Bland-Hawthorn

We construct all axi-symmetric non-gradient $m$-quasi-Einstein structures on a two-sphere. This includes the spatial cross-section of the extreme Kerr black hole horizon corresponding to $m=2$, as well as a family of new regular metrics…

Differential Geometry · Mathematics 2026-05-20 Alex Colling , Maciej Dunajski , Hari Kunduri , James Lucietti

We present a theoretical and numerical study of a dual metasurface superlens dedicated to the near field optical imaging of submicron objects. Compared to the previous studies of dual metasurface plasmonic superlenses, we suggest a more…

Optics · Physics 2019-12-04 Masoud Sharifian Mazraeh Mollaei , Constantin Simovski

This article presents research work on a spectroscopic survey telescope. Our idea is as follows: for such a telescope, a pure reflecting optical system is designed, which should have an aperture and a field of view (FOV) both as large as…

Instrumentation and Methods for Astrophysics · Physics 2024-03-20 Ding-qiang Su , Hua Bai , Xiangyan Yuan , Xiangqun Cui

Several alternative possibilities of how to create an electromagnetic device being able to reconstruct near-field distribution of a source with sub-wavelength resolution (so-called perfect lens) are considered. It is shown that there is a…

Materials Science · Physics 2007-05-23 Stanislav Maslovski , Sergei Tretyakov

The paper describes the MAGIC multi-mode focal reducer (Monitoring of Active Galaxies by Investigation of their Cores), commissioned on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences…

Binary systems have long been recognized as the source of powerful astrophysical diagnostics. Among the many applications of binary stars, they have been used as probes of stellar structure and evolution (both of single and binary stars) in…

Astrophysics · Physics 2007-05-23 Ignasi Ribas

I argue that there is a crisis in optical Astronomy due to a paucity of telescopes and thus the need for a paradigm shift in telescope technology. Large increases in collecting areas and observing time/astronomer are only possible if we…

Astrophysics · Physics 2007-05-23 E. F. Borra

Wide field of view and light weight optics are critical for advanced eyewear, with applications in augmented/virtual reality and night vision. Conventional refractive lenses are often stacked to correct aberrations at wide field of view,…

Glints of light from specular reflection of the Sun are a technosignature of artificial satellites. If extraterrestrial intelligences have left artifacts in the Solar System, these may include flat mirror-like surfaces that also can glint.…

Earth and Planetary Astrophysics · Physics 2020-02-04 Brian C. Lacki

The displacement of star images by atmospheric refraction observed by an Earth-bound telescope is dominated by a familiar term proportional to the product of the tangent of the zenith angle by the refractivity at the ground. The manuscript…

Instrumentation and Methods for Astrophysics · Physics 2015-03-02 Richard J. Mathar

After discussing some subtle issues concerning the computation of deflection angle, a general but simple expression of bending angle of light rays in weak deflection limit has been presented for a general static and spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2010-07-21 Arunava Bhadra

A long-standing problem of astrophysical research is how to simultaneously obtain spectra of thousands of sources randomly positioned in the field of view of a telescope. Digital Micromirror Devices, used as optical switches, provide a most…

Instrumentation and Methods for Astrophysics · Physics 2009-02-17 M. Robberto , A. Cimatti , A. Jacobsen , F. Zamkotsian , F. M. Zerbi
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