Speaker
Balázs Pozsgay
Description
In a CFT with a defect the scaling operators can have non vanishing mean values. At one loop order in planar N=4 SYM the normalization constants of these one-point functions are given by the overlaps between the corresponding Bethe states and a particular Matrix Product State (MPS). These MPS are not eigenstates of the spin chain, but they display very special features: the overlaps are non-zero only for parity symmetric Bethe root configurations, and can be expressed in a factorized form. In this talk we focus on the algebraic properties of these MPS: we explain their relation to boundary integrability and the twisted Yangian, and show how they can be obtained from the twisted Boundary Yang-Baxter relation.
