Information metric on the boundary

A bstract The information metric on the space of boundary coupling constants in two-dimensional conformal field theories is studied. Such a metric is related to the Casimir energy difference of the theory defined on an interval. We concretely compute the information metric on the boundary conformal manifold of free boson CFT as well as SU(2) k WZW theory, obtaining the result expected from the symmetry of the systems. We also compute the information metric on the space of non-conformal boundary states produced by boundary mass perturbations in the theory of a real free scalar. The holographic dual of the boundary information metric in the context of AdS 3 /BCFT 2 is also discussed. We argue that it corresponds to the area of the minimal cross section of the end-of-the-world brane connecting two boundaries of the asymptotic BCFTs.