arXiv2026
We study wavefunctions of quantum gravity in asymptotically AdS$_3$ spacetimes and their relation to $T\bar{T}$-deformed torus partition functions. We show that the deformed partition function is given by an invertible integral transform of bulk wavefunctions, which implements a change of representation from the York time to its conjugate, the spatial volume. The invertibility of the transform allows the bulk wavefunction to be reconstructed from the family of $T\bar{T}$-deformed partition functions. A $T\bar{T}$-deformed partition function at fixed coupling is the amplitude of the bulk state in a finite-width, fixed-volume wavepacket localized at the asymptotic boundary in York time. In the CFT limit, the wavepacket localizes at the boundary, recovering the standard holographic relation. The holographic screen of a given state is the support of the integrand of the transform: at large central charge, it separates from the wavepacket and reproduces finite-cutoff holography for the sign of the coupling with complex energies, and glue-on holography for the opposite sign. In Euclidean signature, the construction arises naturally from wavefunctions of Rindler AdS$_3$, while after a double Wick rotation it admits a Lorentzian interpretation in terms of closed AdS$_3$ torus universes without asymptotic boundaries. We also discuss de Sitter torus universes and generalizations to other spatial topologies and higher dimensions.