3450 — A Vacuum State Alone Does Not Authorize Feedback Attenuation
A distinguished vacuum initializes an environment but does not construct an interaction. Selective feedback attenuation requires a two-port unitary, visible and environment projections, and a termination rule.
Both incidence legs must carry the factor to produce the round-trip factor . Minimal dilations have canonical visible behavior but are unique only up to an environment-frame unitary.
Multiplicative composition additionally requires fresh vacuum, reset, or Fock factorization. Reusing one coherent environment introduces memory and can destroy the product law.
Research packet: research/kitaev/a-vacuum-state-alone-does-not-authorize-feedback-attenuation.md
Scope: no theta environment port, mixing constructor, or compressed-index theorem is derived. No build or checker was run under the operator's research-only instruction.
Durable verification: epistemic graph event ev-000000007394-08666228-bb0d-4172-bd55-b377c2ca155a.