Name: Junaid Saif Khan
Supervisor: Dr. Babar Ahmed Qureshi (Google Scholar profile)
Institution: Department of Physics, Lahore University of Management Sciences
Despite the successes of string theory in describing perturbative gravity, a non-perturbative description of quantum gravity is still elusive and not understood. At the same time, non-perturbative, strong coupling dynamics of gauge theories have not been amenable to direct analytical methods. AdS/CFT duality connects gravity in AdS space to gauge theories living on the boundary of this space via a strong to weak coupling duality thus giving the strong coupling definition of either theory in terms of the week coupling perturbative processes in the other. This idea has got more general applicability as a concept called holograph connecting gravitational theories to quantum theories in one lower dimension.
In this thesis, we have studied this correspondence by studying the dynamics of strings and branes. D-Branes are multidimensional objects on which open strings can end. AdS/CFT correspondence has been derived by studying the low energy action of open strings on a stack of N D3-branes, which is , Super Yang-Mills action and low energy limit of open strings, which is supergravity. The D-brane acts as a source in supergravity and metric is derived in a particular limit. At low energies and small string coupling, the gravity theory in the bulk and the gauge theory on the brand decouple and describe the same physics giving rise to AdS/CFT. We have also calculated the correlation functions of gravity and gauge theories that turned out to be the same on both sides of the duality. By using this, we studied the holographic principle and verified that AdS/CFT correspondence is a realization of the holographic principle.
Thesis and Presentations
Mid-year presentation (Download Link)
Thesis (Download Link)