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Related papers: A Natural Formalism for Microlensing

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I show that when the observables $(\vec \pi_{{\rm E}},t_{{\rm E}},\theta_{{\rm E}},\pi_s,\vec \mu_s)$ are well measured up to a discrete degeneracy in the microlensing parallax vector $\vec \pi_{{\rm E}}$, the relative likelihood of the…

Instrumentation and Methods for Astrophysics · Physics 2020-12-02 Andrew Gould

We employ VLTI GRAVITY to resolve, for the first time, the two images generated by a gravitational microlens. The measurements of the image separation \theta_{-,+}=3.78 +/- 0.05 mas, and hence the Einstein radius \theta_E =1.87 +/- 0.03…

We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…

Astrophysics · Physics 2009-11-07 Eric Agol

I present a novel method for measuring lens masses for microlensing events. By combining a measured lens flux with the microlens parallax vector pi_E, it is possible to derive the mass of the lens system without knowing the angular size of…

Earth and Planetary Astrophysics · Physics 2015-09-30 Jennifer C. Yee

I present a somewhat selective review of microlensing theory, covering five major areas: 1) the derivation of the basic formulae, 2) the relation between the observables and the fundamental physical parameters, 3) binaries, 4) astrometric…

Astrophysics · Physics 2007-05-23 Andrew Gould

We consider strong gravitational lensing by nearby stars. Using our wave-optical treatment of lensing phenomena, we study Einstein rings that may form around nearby stellar lenses. It is remarkable that these rings are bright and large…

Instrumentation and Methods for Astrophysics · Physics 2023-02-13 Slava G. Turyshev , Viktor T. Toth

It is known that a relative translational motion between the deflector and the observer affects gravitational lensing. In this paper, a lens equation is obtained to describe such effects on actual lensing observables. Results can be easily…

Astrophysics · Physics 2008-11-26 M. Sereno

We present a framework that reformulates gravitational lensing as an optical phenomenon governed by an effective refractive index, enabling exploration of modified gravity theories using undergraduate-level mathematics and optics. After…

General Relativity and Quantum Cosmology · Physics 2026-04-09 Romy Hanang Setya Budhi

The lensing at large deflection angles caused by a Schwarzschild black hole for the case of a nonminimal coupling between gravitation and electromagnetism is examined. We show that photons follow an effective geometry, which displays an…

General Relativity and Quantum Cosmology · Physics 2020-07-01 Santiago E. P. Bergliaffa , Edson Elias de Souza Filho , Rodrigo Maier

We study gravitational lensing by compact objects in gravity theories that can be written in a Post-Post-Newtonian (PPN) framework: i.e., the metric is static and spherically symmetric, and can be written as a Taylor series in m/r, where m…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Charles R. Keeton , A. O. Petters

Interferometric observations of microlensing events have the potential to provide unique constraints on the physical properties of the lensing systems. In this work, we first present a formalism that closely combines interferometric and…

Earth and Planetary Astrophysics · Physics 2016-03-09 A. Cassan , C. Ranc

We analyze PLANET photometric observations of the caustic-crossing binary-lens microlensing event, EROS BLG-2000-5, and find that modeling the observed light curve requires incorporation of the microlens parallax and the binary orbital…

In this paper we prove a number of exact relations between optical observables, such as trigonometric parallax, position drift and the proper motion of a luminous source in addition to the variations of redshift and the viewing angle. These…

General Relativity and Quantum Cosmology · Physics 2025-05-13 Mikołaj Korzyński , Nezihe Uzun

The standard light curve of a microlensing event provides only two constraints on the six unknown parameters of the lens. We show that narrow-band photometry during a microlensing event of a giant star can in addition determine the angular…

Astrophysics · Physics 2009-10-28 Abraham Loeb , Dimitar Sasselov

We develop the General Theory of Relativity in a formalism with extended causality that describes physical interaction through discrete, transversal and localized pointlike fields. The homogeneous field equations are then solved for a…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Manoelito M. de Souza , Robson N. Silveira

The gravitational microlensing as a unique astrophysical tool can be used for studying the atmosphere of stars thousands of parsec far from us. This capability results from the bending of light rays in the gravitational field of a lens…

Solar and Stellar Astrophysics · Physics 2015-08-06 Sedighe Sajadian , Sohrab Rahvar

In this paper, we investigate the applicability of the astrometric method to the determination of the lens parameters for gravitational microlensing events toward both the LMC and the Galactic bulge. For this analysis, we investigate the…

Astrophysics · Physics 2009-10-30 Cheongho Han , Kyongae Chang

In order to understand the nature of the lenses that generate microlensing events, one would like to measure their mass, distance, and velocity. Unfortunately, current microlensing experiments measure only one parameter of the events, the…

Astrophysics · Physics 2009-10-28 B. Scott Gaudi , Andrew Gould

Microlensing studies are usually based on the lens equation that is valid only to the first order in the gravitational constant G and lens mass M. We consider corrections to the conventional lens equation in terms of differentiable…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-03 Hideki Asada

Astrometric microlensing will offer in the next future a new channel for investigating the nature of both lenses and sources involved in a gravitational microlensing event. The effect, corresponding to the shift of the position of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 A. A. Nucita , F. De Paolis , G. Ingrosso , M. Giordano , L. Manni
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