Ringdown Without Λ: A π-Invariant Single-Mode Explanation and a Clean Energy Budget

This article presents the final stage of the Static Vibrational Reality (SVR) framework, showing that ringdown data can be fully explained by a single, weakly-damped oscillator. In this minimal model, the invariant relation Q·(T/τ) ≈ π emerges naturally from second-order dynamics, without the need for a corrective Λ sector. By anchoring optical power to an absolute photometric reference and explicitly accounting for thermal and afterglow channels, the energy budget closes cleanly. The previously introduced “0.6 keV” term is reinterpreted as bookkeeping for unmodeled thermal/memory effects, rather than a physical hidden sector. The slow ~31 nHz feature remains present, but as a regulatory timescale associated with thermal/environmental memory, not as an energy quantum. The conclusion is scientifically modest: nothing extraordinary is required—ringdowns are described by ordinary physics, with π appearing as a natural invariant and the energy ledger balancing when all channels are included.