Further on the Aharonov-Bohm Green function: the coincidence limit

Abstract

For a scalar CFT with a monodromy defect, a `subtracted Green function' is derived in terms of an Appell $F_1$ function. A conjectured relation of Gimenez-Grau and Liendo is thereby proved and extended and shown to hold for generalised free fields. A possible means of determining the bulk block expansion is outlined. Finite coincidence limits are expressed as combinations of Beta functions.

8 pages. Typing and other errors corrected. Comment added regarding the bulk block expansion