Strings as sigma models and in the tensionless limit
| dc.creator | Persson, Jonas | |
| dc.date | 2007-05-16 | |
| dc.date.accessioned | 2026-07-07T13:03:56Z | |
| dc.date.available | 2026-07-07T13:03:56Z | |
| dc.description | This thesis considers two different aspects of string theory, the tensionless limit of the string and supersymmetric sigma models. The tensionless limit is used to find a IIB supergravity background generated by a tensionless string. Quantization of the tensionless string in a pp-wave background is performed and the tensionless limit is found to commute with quantization. Further, the sigma model with N=(2,2) extended world-sheet supersymmetry is considered and the requirement on the target space to have a bi-Hermitean geometry is reviewed. It is shown that the equivalence between bi-Hermitean geometry and generalized Kahler follows, in this context, from the equivalence between the Lagrangian- and Hamiltonian formulation of the model. Moreover, the explicit T-duality transformation in the Hamiltonian formulation of the sigma model is constructed and shown to be a symplectomorphism. Under certain assumptions, the amount of extended supersymmetry present in the sigma model is shown to be preserved under T-duality. Further, by requiring N=(2,2) extended supersymmetry in a first order formulation of the sigma model an intriguing geometrical structure arises and in a special case generalized complex geometry is found to be contained in the new framework. | |
| dc.description | PhD Thesis, viii+127 pages | |
| dc.identifier | https://arxiv.org/abs/0705.2346 | |
| dc.identifier | http://arxiv.org/abs/0705.2346 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/226987 | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Strings as sigma models and in the tensionless limit | |
| dc.type | text |