D-branes, gauge theory and string field theory

In this thesis, we present several works done in last three years. They include three directions in the string theory. In the first direction, we use the brane setup to find mirror pairs of SO(n) and Sp(k) gauge groups for N = 4 three-dimensional gauge field theories. To reach this result, we analyze carefully the s-configuration and predict a nontrivial string dynamics, i.e., the splitting of branes on the orientifold planes. In the second direction, we develop the "inverse algorithm" and use it to get nontrivial world volume theories of D-branes probing more exotic singularities. In this process, we find the "toric duality" which relates different phases of D-brane probe theories. We realize later that the toric duality is an example of the more powerful Seiberg-duality so these different phases are related by the Seiberg duality. In the third direction, by using numerical calculation we get a strong evidence to support the second conjecture of Sen's three conjectures. We show that if the identity field is BRST exact state around the tachyon vacuum, the open string spectrum will decouple from the physics and leave only the closed string spectrum.

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

• Feng, Bo, 1971-

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/1721.1/8491

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8491