A Natural Formalism for Microlensing
Abstract
If the standard microlensing geometry is inverted so that the Einstein ring is projected onto the observer plane rather than the source plane, then the relations between the observables (θ_{E},r_{E}) and the underlying physical quantities (M,π_{rel}) become immediately obvious. Here θ_{E} and r_{E} are the angular and projected Einstein radii, M is the mass of the lens, and π_{rel} is the lenssource relative parallax. I recast the basic formalism of microlensing in light of this more natural geometry and in terms of observables. I then find that the relations between observable and physical quantities assume an exceptionally simple form. In an appendix, I propose a set of notational conventions.
 Publication:

The Astrophysical Journal
 Pub Date:
 October 2000
 DOI:
 10.1086/317037
 arXiv:
 arXiv:astroph/0001421
 Bibcode:
 2000ApJ...542..785G
 Keywords:

 Astrometry;
 Cosmology: Gravitational Lensing;
 Astrophysics
 EPrint:
 8 pages, 1 figure tells all. Interested parties are requested to vote on a proposed standard for microlensing notation given in the appendix. Submitted to ApJ