Diploma thesis in physics

Deutsche Fassung

Two-Dimensional Models of Black Hole Radiation

This diploma thesis, which I finished in the winter term 1999/2000 at the Insitute of Theoretical Physics of the Friedrich Schiller University of Jena, completed my physics study begun in 1995.

In 2004, this diploma thesis was cited by Bryan Grob's matriculation thesis »Wie schwarz sind Schwarze Löcher?« («How black are Black Holes?»).

The subject of the thesis

My diploma thesis is about theoretical physics, and more specifically, quantum field theory in curved spacetime. The phenomenon the thesis is about is the Hawking effect. It describes the radiation of particles that is - according to this theory - emitted from Black Holes.

What makes the Hawking effect interesting is the fact that it can be calculated in the framework of a four-dimensional quantum field theory. Such a theory is thought to describe the world we live in according to Einstein. Unfortunately, it is so complicated mathematically that it has few practical applications.

In order to get some hints for dealing with the full four-dimensional theory, one considers simpler theories that are easier to handle mathematically. Such a simplification could consist in confining oneself to systems with certain symmetries. Then all physical processes can be described by less than four (e.g. two) coordinates, and one gets a simpler theory for the special case considered.

Such simplifications can be obtained in a number of ways, and it is not clear in the first place which is the best. The aim of my work was to investigate several two-dimensional models with respect to how well they approximate the four-dimensional theory. The comparison was done regarding Hawking radiation as it is sufficiently well-known both for the two- and four-dimensional theory.