Time from a Timeless Universe with Quantum Geometry: An Exact Emergence-of-Time Identity
Mustafa Boudjerada
This note studies the emergence of time in a timeless quantum universe using a Wheeler–DeWitt-style constrained model with quantum geometry, clocks, and matter records. The model contains no external time parameter. The total state satisfies a timeless constraint while the geometry register, clock, and matter systems remain fully quantum and entangled. Despite the absence of fundamental time, conditioning on the clock and geometry recovers branch-dependent Schrödinger evolution with the correct redshifted proper-time rates. The work shows that quantum geometry can act as a reference frame for time. An observer without access to the geometry register carries a geometric information deficit, while conditioning on the geometry restores the individual geometric branches exactly. Superposed geometries generate proper-time interference, with matter records determining the transition between quantum time-history interference and classical branch evolution. The central result is an exact emergence-of-time identity: the observable coherence between different geometry branches is equal to the product of geometry coherence and matter-record overlap. When geometry information is fully recorded by matter, the interference between different time histories disappears, and each branch exhibits its own classical Schrödinger evolution. The note also derives a continuous crossover law: the emergence of classical time depends quantitatively on how strongly matter measures the quantum geometry. This connects the relational-time mechanism of Page–Wootters with the semiclassical time program of Kiefer and Zeh in an exactly solvable setting. The results are obtained in finite Wheeler–DeWitt-style toy models with declared assumptions: quantum geometry registers, simplified redshift structure, and no claim of a complete theory of dynamical quantum gravity. Verification and reproducibility materials are included.
•Aug 25, 2026•0 citations