Radial canonical AdS$_3$ gravity and $T\bar{T}$

Abstract: We employ an ADM deparametrization strategy to discuss the radial canonical formalism of asymptotically AdS$_3$ gravity. It leads to the identification of a radial 'time' before quantization, which is the volume time, canonically conjugate to York time. Holographically, this allows to interpret the semi-classical path integral of $T\bar T$ theory as a Schr\"odinger wavefunctional satisfying a Schr\"odinger evolution equation in volume time, and the $T\bar T$ operator expectation value in terms of the Hamiltonian that generates volume time translations -- both consistent with cut-off holography. We make use of the canonical perspective to construct the rotating BTZ solution from the Hamilton-Jacobi equation, with a finite cut-off energy spectrum that has a known holographic $T\bar T$ interpretation, as well as semi-classical Wheeler-DeWitt states for that solution.