Smooth particles and exotic strings

• During the last few decades quantum gauge field theories in general, and the Electroweak Standard Model in particular, have been very successful in the description of the fundamental constituents of matter and their interactions. However, such models all meet with severe shortcomings, e.g. it does not seem possible to incorporate gravitation into this framework, and there is also a certain arbitrariness in all such models. It would thus be highly desirable to find a more fundamental theory where gravitation can be naturally incorporated. The most successful candidates for such a truly unified theory at present are String Theories. Here the basic objects are not, as is usually the case, point particles, but one-dimensional objects—strings.The thesis consists of investigations on some point particle and string models. Topics treated are: the quantization of a smooth particle, which is a particle with a higher derivative action that can be derived from the Nambu- Goto string in a certain limit. Furthermore such a particle with world-line supergravity is constructed. Concerning strings there is a study of stringlike solutions to field theories, especially solutions to effective theories that behave as strings but with a higher derivative action; and finally quantum mechanics of strings in the limit of vanishing string tension.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

Physics

fysik

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