Preprint: Introduces the Temporal Envelope Theory (TET) framework, treating Tₑ = ℏ/ΔEₑff as the physical causal duration of a quantum state — an independently measurable engineering parameter, not a notation. Recovers Fermi's Golden Rule, Lindblad, and all standard decoherence limits analytically. Derives the Temporal Photoelectric Effect: dephasing vanishes exactly when η = δE/ΔEₑff = 2πn. Cross-route consistency verified to six significant figures across five platforms.
neal andrew kydd (Mon,) studied this question.