Correlation functions on conical defects

We explore a technique recently proposed in [1] and suggest a correspondence between the N-point correlation functions on a conifold and the (N+1)-point correlation functions on a regular manifold. This correspondence suggests a new systematic way to evaluate the correlation functions on a manifold with conical defect. We apply the correspondence to study the vacuum expectation value of a scalar operator and of the energy-momentum tensor in a conformal field theory living on a spacetime with conical singularity. Our findings agree with the existing calculations for a cosmic string spacetime. We use the correspondence to carry out calculations for the generic scalar operator and conserved vector current. For a unitary field theory we also compute the expectation value of the energy-momentum tensor using the spectral representation of a two-point function of the energy-momentum tensor in Minkowski spacetime.