Aspects of branes and orbifolds in string theory

The main theme of this thesis is branes and orbifolds in string theory, with some digression towards other directions in the final chapters. After reviewing background material on D-branes and orbifolds, along with some mathematical fundamentals, I describe the following results. First, a classification of discrete torsion for a large class of orbifolds and a technique for extracting the matter content of D-brane probe gauge theories on orbifolds with discrete torsion. Subsequently, I discuss an algorithm, called stepwise projection, that illuminates the structure of the so-called exceptional quivers, and hints towards the brane realization of the associated gauge theories. Next, I present the computation of the partition function of the coset conformal field theory describing the two-dimensional black hole. This computation confirms earlier results concerning the spectrum of the black hole and it enable us to identify the physical Hilbert space. This theory appears in the exact string theory description of configurations of Neveu-Schwarz 5-branes and in the conformal field theory description of certain orbifolds in singular limits; thus, it is only a mild digression from the main theme of the thesis. This is not so, however, for the last topic discussed here. We will change gears completely and discuss our extension of Witten's construction of boundary string field theory to the superstring. As in the bosonic case, the main tool we use is the Batalin-Vilkovisky formalism. Our construction proves a recent conjecture regarding the spacetime action of the supersymmetric theory and a related conjecture concerning quantum field theories on two-dimensional spaces with boundaries.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2002

Author dc:creator

• Prezas, Nikolas, 1973-

Advisor dc:contributor.advisor

• Amihay Hanany.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8486

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8486