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Related papers: Gravitational Microlensing in NUT Space

200 papers

In the framework of the search of dark matter in galactic halos in form of massive compact halo object (MACHOs), we discuss the status of microlensing observations towards the Magellanic Clouds and the Andromeda galaxy, M31. The detection…

Astrophysics · Physics 2010-11-11 S. Calchi Novati

The mathematical theory of gravitational lensing has revealed many generic and global properties. Beginning with multiple imaging, we review Morse-theoretic image counting formulas and lower bound results, and complex-algebraic upper bounds…

Astrophysics of Galaxies · Physics 2014-11-20 A. O. Petters , M. C. Werner

Gravitational microlensing of gravitational waves (GWs) opens up the exciting possibility of studying the spacetime geometry around the lens. In this work, we investigate the prospects of constraining the `charged' hair of a charged…

General Relativity and Quantum Cosmology · Physics 2025-03-12 Uddeepta Deka , Sumanta Chakraborty , Shasvath J. Kapadia , Md Arif Shaikh , Parameswaran Ajith

Recent discussion of the effects of finite source size on high magnification microlensing events due to MACHOs motivates a study into the feasibility of observing such effects and extracting the source radius. Simulated observations are…

Astrophysics · Physics 2009-10-28 Eric Peng

Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this…

Instrumentation and Methods for Astrophysics · Physics 2017-06-15 A. J. Harding , R. Di Stefano , S. Lépine , J. Urama , D. Pham , C. Baker

In the cold dark matter scenario, dark matter halos are assembled hierarchically from smaller subunits. Some of these subunits are disrupted during the merging process, whereas others survive temporarily in the form of subhalos. A…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 E. Zackrisson , T. Riehm

Optical and X-ray observations of strongly gravitationally lensed quasars (especially when four separate images of the quasar are produced) determine not only the amount of matter in the lensing galaxy but also how much is in a smooth…

Microlensing promises to be a powerful tool for studying distant galaxies and quasars. As the data and models improve, there are systematic effects that need to be explored. Quasar continuum and broad-line regions may respond differently to…

Astrophysics · Physics 2008-11-26 Arthur B. Congdon , Charles R. Keeton , S. J. Osmer

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2009-11-10 Philippe Jetzer , Sebastiano Calchi Novati

The detection of microlensing events from stars in the Large Magellanic Cloud and in the Galactic bulge raise important constraints on the distribution of dark matter and on galactic structure, although some events may be due to a new type…

Astrophysics · Physics 2020-11-25 David Valls-Gabaud

The EROS and MACHO collaborations have reported observations of light curves of stars in the Large Magellanic Cloud that are compatible with gravitational microlensing by intervening massive objects, presumably Brown-Dwarf stars. The OGLE…

Astrophysics · Physics 2015-06-24 A. de Rujula , G. Giudice , S. Mollerach , E. Roulet

Weak gravitational lensing is a unique probe of the dark side of the universe: it provides a direct way to map the distribution of dark matter around galaxies, clusters of galaxies and on cosmological scales. Furthermore, the measurement of…

Astrophysics · Physics 2010-01-07 Henk Hoekstra , Bhuvnesh Jain

It has been argued in a number of recent papers that dark matter is in the form of Jupiter mass primordial black holes which betray their presence by microlensing quasars. This lensing accounts for a number of characteristic properties of…

Astrophysics · Physics 2009-10-30 M. R. S. Hawkins

Weak gravitational lensing of distant galaxies can probe the total projected mass distribution of foreground gravitational structures on all scales and has been used successfully to map the projected mass distribution of rich intermediate…

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

Basics of standard theory of microlensing are introduced. Results of microlensing observations toward Magellanic Clouds and relations with dark matter (DM) problem in our Galaxy are described. Pixel microlensing observations and recent…

Astrophysics · Physics 2007-05-23 Alexander F. Zakharov

The motivation for this paper is to review the limits set on the MACHO content of the Galactic halo by microlensing experiments in the direction of the Large Magellanic Cloud. This has been prompted by recent measurements of the Galactic…

Astrophysics of Galaxies · Physics 2015-03-09 M. R. S. Hawkins

We study the gravitational lensing in the weak field approximation assuming the presence of a plasma and of a magnetic field around a compact gravitational source. The external magnetic field causes the split of the image, as the…

General Relativity and Quantum Cosmology · Physics 2020-02-19 Bobur Turimov , Bobomurat Ahmedov , Ahmadjon Abdujabbarov , Cosimo Bambi

When gravitational waves propagate near massive objects, their paths curve resulting in gravitational lensing, which is expected to be a promising new instrument in astrophysics. If the time delay between different paths is comparable with…

General Relativity and Quantum Cosmology · Physics 2022-07-14 Oleg Bulashenko , Helena Ubach

The luminosity variation of a stellar source due to the gravitational microlensing effect can be considered also if the light rays are defocused (instead of focused) toward the observer. In this case, we should detect a gap instead of a…

After a decade of gravitational microlensing experiments, a dozen of microlensing candidates in the direction of the stars of the Large Magellanic Cloud (LMC) have been detected by the EROS and MACHO groups. Recently it was shown that the…

Astrophysics · Physics 2009-11-10 Sohrab Rahvar