No redshift comb in 7 million DESI objects: a sky-coherent test of redshift periodicity with DESI Data Release 1

Claims that cosmological redshifts are quantized or periodic have recurred for five decades. We test for a periodic comb in ln(1+z) using 7 319 883 objects from the first data release of the Dark Energy Spectroscopic Instrument (DESI DR1): bright galaxies, luminous red galaxies and quasars over 0.01<z<3.5. A cosmological comb, as predicted by models in which redshift accrues in discrete collective steps, must appear in the redshift of every object with the same phase in every direction. We remove the smooth redshift distribution of each sky region and search 32 sky patches per tracer for phase-coherent periodicity with steps 5×10⁻⁴<ε<2×10⁻². No sample exceeds its 99% look-elsewhere-corrected threshold. Synthetic combs injected into the real catalogs are detected in all of 200 injections per case for ε≥0.002–0.003, and a comb followed by only 10% of the objects is detected at ε=0.003. A model-independent cross-correlation of the two Galactic caps also excludes irregular collective ladders with mean steps above about 0.002. Three comb-free AbacusSummit mocks behave like the data. Finally, the large periods claimed in earlier work acquire naive significances of tens to hundreds of standard deviations from the survey selection function alone, and a comb-free mock reproduces them.