Open Strings in PP-Wave Background from Defect Conformal Field Theory

TL;DR

The work extends the BMN program to open strings ending on a D5-brane in a pp-wave background obtained from the Penrose limit of $AdS_5\times S^5$. It constructs a complete dictionary of gauge-invariant defect-CFT operators dual to open-string states, encoding boundary conditions through symmetry breaking and defect couplings and reproducing the open-string light-cone spectrum via anomalous dimensions. The results provide a concrete open-string/defect-CFT map with a calculable spectrum in the strong coupling limit, and suggest natural generalizations to multiple D5-branes and other defect setups. This advances the understanding of AdS/CFT with defects and the solvability of string theory in RR backgrounds beyond supergravity.

Abstract

We consider open strings ending on a D5-brane in the pp-wave background, which is realized in the Penrose limit of $AdS_5 \times S^5$ with an $AdS_4\times S^2$ brane. A complete list of gauge invariant operators in the defect conformal field theory is constructed which is dual to the open string states.