Inverse Hamiltonian Reconstruction from Gravitational Energy Density in Curved Spacetime

Abstract

We present a general framework for reconstructing effective Hamiltonians from known gravitational energy density profiles in curved spacetime. Starting from local thermal equilibrium and Liouville dynamics, we establish an inverse procedure that relates the macroscopic energy density \( \rho(x) \) to a distribution function \( f(x,p) \sim e^{-\beta H(x,p)} \), and recovers the underlying Hamiltonian \( H(x,p) \) via functional inversion. This approach synthesizes tools from relativistic kinetic theory, statistical mechanics, and covariant gravitational thermodynamics, offering a systematic way to extract microscopic dynamics from coarse-grained energy observables. Applications include FLRW cosmology, Loop Quantum Gravity corrections, AdS/CFT holography, and the SYK model. Our results provide a novel route for probing emergent spacetime dynamics through observable densities, bridging geometry, entropy, and Hamiltonian flow in curved backgrounds.