Day reflection tests with independent days do not detect width order in 251 FAST burst pairs with 10–300 ms gaps

We tested whether later bursts have greater equivalent widths in close pairs from two public FAST catalogs. Equivalent width is fluence divided by peak flux density. The fixed main test used successive bursts with gaps from 10 to 300 milliseconds. It selected 82 pairs from FRB 20121102A and 169 from FRB 20201124A. We summed log width ratios within days and reflected complete days. The null assumes independent days and symmetry under day reflection. The geometric mean later-to-earlier width ratios were 1.0543 and 1.0867. The raw two-sided p-values were 0.524055 and 0.051785. After Holm adjustment for two sources, they were 0.524055 and 0.103570. Neither source passed the main test at a 0.05 level. The unadjusted day bootstrap intervals were 0.9033–1.2347 and 1.0064–1.1724. These descriptive intervals use a different calibration from the reflection test. A fixed check that includes gaps below 10 milliseconds gave a stronger Li result: 340 pairs, ratio 1.0908, and unadjusted p = 0.025735. That check has no correction for the set of checks. Burst separation rules, detection, and measured width can affect the result. The main result does not establish equal widths or exclude a physical time direction. The package preserves source data, provenance, code, pair ledgers, figures, and an independent Decimal check. A fresh offline run reproduced all 12 analysis files byte for byte.

fast radio bursts · FAST · equivalent width · duration order · time reversal · day reflection · public data · reproducible research