  In this work we discuss the holographic description of states in the Hilbert
space of (2+1)-dimensional quantum gravity, living on a time slice in the bulk.
We focus on pure gravity coupled to pointlike sources for heavy spinning
particles. We develop a formulation where the equations for the backreacted
metric reduce to two decoupled Liouville equations with delta-function sources
under pseudosphere boundary conditions. We show that both the semiclassical
wavefunction and the gravity solution are determined by a universal object,
namely a classical Virasoro vacuum block on the sphere. In doing so we derive a
version of Polyakov's conjecture, as well as an existence criterion, for
classical Liouville theory on the pseudosphere. We also discuss how some of
these results are modified when considering closed universes with compact
spatial slices.
