Gravitationslinser
Gravitational lenses are unlike ordinary optical lenses, a phenomenon corrupting our optical view of the cosmos. When we look out intospace we see celestial bodies lying with astronomical distance from Earth. There is no guarantee that what we see out there in space is actually there where we are observing it, and it may be that we see multiple images of the same star! Studies have shown that thenumber of distorted images of an n-mass (n > 1) plane lens can not exceed 5(n -1) for lighter lenses or 5n for more massive lens. This mathematical thesis covers gravitational lensing and their properties that distort light rays coming towards us from distant celestial bodies. In addition of gravitational lensing, its properties and the proof of the maximum number of distorted images, a bigger part of this work even cover two very interesting mathematical tools - the so-called Schwarz function and Bezout theorem.