Liouville field theory on a pseudosphere
A. Zamolodchikov, Al. Zamolodchikov
TL;DR
Liouville field theory on the pseudosphere provides a controlled setting to study 2D quantum gravity with boundary of constant negative curvature. The authors solve the out-vacuum bootstrap, modular bootstrap and boundary bootstrap to classify admissible boundary data, revealing an infinite family of out-vacua $U_{m,n}(\alpha)$ tied to degenerate Virasoro representations. The basic $ (m,n)=(1,1) $ vacuum emerges as the perturbatively natural quantization with no nontrivial boundary operators, while other vacua exhibit richer boundary content and modular data consistent with fusion rules. Collectively, these results establish a concrete operator content, fusion structure, and boundary dynamics for Liouville theory on a hyperbolic background, offering insights into 2D quantum gravity and potential AdS2/CFT connections.
Abstract
Liouville field theory is considered with boundary conditions corresponding to a quantization of the classical Lobachevskiy plane (i.e. euclidean version of $AdS_2$). We solve the bootstrap equations for the out-vacuum wave function and find an infinite set of solutions. This solutions are in one to one correspondence with the degenerate representations of the Virasoro algebra. Consistency of these solutions is verified by both boundary and modular bootstrap techniques. Perturbative calculations lead to the conclusion that only the ``basic'' solution corresponding to the identity operator provides a ``natural'' quantization of the Lobachevskiy plane.
