A sharp-switch scalar solution

For $t>0$, the terms $1/4+\mathrm{i}\lambda t/2$ solve the homogeneous scalar equation. The linear term is $O(\lambda )$ on a fixed bounded time interval.

This $H$ is not ${\sigma }_{\epsilon }$. Neither Lemma lem:ode-residual nor Lemma lem:sharp-ode is a model or evaluation of the gravitational insertion, a value of the selected graviton inverse, or a cancellation of the XI-G witness.