The magnification theorem
O. Wucknitz [1]
- Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany
Abstract
In this presentation I discuss the magnification theorem according to which
any realistic mass distribution will always produce at least one image with a
magnification above unity. To avoid the paradox that total flux would not be
conserved, this theorem can only be valid if the un-lensed situation used for
comparison is defined in such a way that the area over which the flux is
distributed is different from the lensed situation. In an alternative scenario
with unchanged total area, the magnification theorem does not hold
anymore. This picture has the advantage that the magnification can be derived
directly from the deflection angle, which is not strictly true in the standard
scenario. As an interesting implication, the Poisson equation has to be
modified to account for the fact that field lines cannot escape the compact
celestial sphere.
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PDF file (1.8 MB, last change 13 Jul 2009)
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Script last modified on 7 Sep 2010
Last change to this data base entry on 13 Jul 2009