We examine the two-point correlation functions of the fields exp(i alp
ha Phi) in the sine-Gordon theory at all values of the coupling consta
nt <(beta)over cap>. Using conformal perturbation theory, we write dow
n explicit integral expressions for every order of the short-distance
expansion. Using a novel technique analogous to dimensional regularisa
tion, we evaluate these integrals for the first few orders finding exp
ressions in terms of generalised hypergeometric functions. From these
derived expressions, we examine the limiting forms at the points where
the sine-Gordon theory maps onto a doubled Ising and the Gross-Neveu
SU(2) models. In this way we recover the known expansions to first sub
leading order of the spin and disorder fields about criticality in the
Ising model and we correct an omission in past calculations of the Ko
sterlitz-Thouless flows in the Gross-Neveu SU(2) model.