The Low-Frequency Turnover of a Background Born at a Bounce

This paper asks a single question: Where would a causal turnover appear in the nanohertz spectrum if part of the background was generated at a bounce, and is that window observable? Working from the published common-process amplitude of 2.4e-15 in characteristic strain at one cycle per year and the standard binary spectral index of thirteen thirds, the study computes the relevant quantities by a broken power-law spectrum whose break frequency follows from the horizon scale at the generating epoch redshifted to today. The headline computed values are break_nHz_at_z1e8 = 1.0. These values are compared throughout with the published pulsar-timing values from the North American, European, Parkes and Chinese arrays. The calculation is fully reproducible from the deposited code, and every headline number appears in the accompanying results file. This study is simulated and computed from stated assumptions; it is not a measurement, and no new timing data are presented.