Method of images in defect conformal field theories

We propose a prescription for describing correlation functions in higher-dimensional defect conformal field theories (DCFTs) by those in ancillary conformal field theories (CFTs) without defects, which is a vast generalization of the image method in two-dimensional boundary CFTs. A correlation function of n operators inserted away from a defect in a DCFT is represented by a correlation function of 2n operators in the ancillary CFT, each pair of which is placed symmetrically with respect to the defect. We establish the correspondence by matching the constraints on correlation functions imposed by conformal symmetry on both sides. Our method has the potential to shed light on new aspects of DCFTs from the viewpoint of conventional CFTs.

Automated summary

We propose a method to describe correlation functions in higher-dimensional defect conformal field theories by using correlation functions in ancillary conformal field theories. This method has the potential to reveal new aspects of defect conformal field theories from the viewpoint of conventional conformal field theories.