Fluence fits give no clear later-session width gain before S/N control in two FRB 20220912A samples

We test whether fluence fits transfer to later width estimates for FRB 20220912A. CHIME gives 168 earlier and 111 later bursts. Nancay gives 473 earlier and 99 later bursts. Against frequency-only fits, later squared log-width error falls by 6.38 and 9.02 percent. Both nominal 95 percent session-bootstrap intervals include zero. After signal-to-noise control, gains are 27.63 and 40.93 percent, with positive intervals. These gains can use measurement coupling: fluence and width enter the radiometer equation and integration windows. They do not confirm an intrinsic energy-duration law. High-S/N CHIME data are too sparse for the planned check. Separate telescope samples use different width definitions and radio bands. No new object or unexplained signal is confirmed. Original code, aggregate evidence, a figure, exact input hashes and external retrieval steps are included. Raw data and record-level derivatives remain outside the baseline bundle.

astronomy · FRB 20220912A · fluence · pulse width · temporal validation · measurement coupling · null result