Three-Point Function in Perturbed Liouville Gravity

Three-point correlation function in perturbed conformal field theory coupled to twodimensional quantum gravity (perturbed Liouville gravity) is explicitly computed by using the free field approach. The representation considered here is the one recently proposed in [1] to describe the string theory in AdS3 space. Consequently, this computation extends previous results which presented free field calculations of particular cases of string amplitudes, and confirms that the free field approach leads to the exact result. Remarkably, this representation allows to compute winding violating three-point functions without making use of the spectral flow operator. Exact agreement is obtained with previous computations of these observables, which were done by following different formalisms.