String integrability of defect CFT and dynamical reflection matrices
Georgios Linardopoulos (Institute of Nuclear and Particle Physics, National Centre for Scientific Research, “Demokritos”, Agia Paraskevi, 153 10, Greece); Konstantin Zarembo (Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, Stockholm, SE-106 91, Sweden, Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, Copenhagen, 2100, Denmark)
The D3-D5 probe-brane system is holographically dual to a defect CFT which is known to be integrable. The evidence comes mainly from the study of correlation functions at weak coupling. In the present work we shed light on the emergence of integrability on the string theory side. We do so by constructing the double row transfer matrix which is conserved when the appropriate boundary conditions are imposed. The corresponding reflection matrix turns out to be dynamical and depends both on the spectral parameter and the string embedding coordinates.