Quantum Liouville theory in the background field formalism I. Compact Riemann surfaces

Using Polyakov’s functional integral approach with the Liouville action functional defined in \cite{ZT2} and \cite{LTT}, we formulate quantum Liouville theory on a compact Riemann surface X of genus g > 1. For the partition function <X> and for the correlation functions with the stress-energy tensor components $<{\prod }_{i=1}^{n}T(z_i){\prod }_{k=1}^l\bar{T}({\text{w}}_k)X>$, we describe Feynman rules in the background field formalism by expanding corresponding functional integrals around a classical solution - the hyperbolic metric on X. Extending analysis in \cite{LT1,LT2,LT-Varenna,LT3}, we define the regularization scheme for any choice of global coordinate on X, and for Schottky and quasi-Fuchsian global coordinates we rigorously prove that one- and two-point correlation functions satisfy conformal Ward identities in all orders of the perturbation theory. Obtained results are interpreted in terms of complex geometry of the projective line bundle ${\text{cE}}_c={\lambda }_H^{c\mathrm{/}2}$ over the moduli space ${\mathfrak{M}}_g$, where c is the central charge and ${\lambda }_H$ is the Hodge line bundle, and provide Friedan-Shenker \cite{FS} complex geometry approach to CFT with the first non-trivial example besides rational models.