Gravitational-Wave Peak Frequency From the Inverse Duration of a Ceiling-Consistent Transition

The benchmark exponent gives beta/H = 1898, a fast transition, and a peak at 40.51 mHz, at the upper edge of the millihertz band targeted by space interferometers. Across the scan, the peak moves from 0.213 mHz at beta/H = 10 to 2.13 mHz at beta/H = 100, a reminder that an order of magnitude in duration is an order of magnitude in frequency and can move a signal between instruments. Because frequency scales linearly with transition temperature, the same durations at 10 TeV would peak a hundred times higher, in the decihertz range. The ceiling enters only as a consistency condition: every temperature in the table lies far below the maximum, so no entry requires correction, and the table can be applied as published. This study is simulated and computed from stated assumptions; it is not a measurement.