The Scalar Spectral Index Across Ten Decades of Wavenumber in a Bounce Spectrum
Year: 2026
Type: article
Abstract: A single spectral index quoted at a pivot scale conceals how much the index itself varies across the full range of scales that different observations probe. This paper tabulates the scalar index of the bounce spectrum from k = 1e-4 to 50 per megaparsec, ten decades short of the full range in logarithmic terms covered by microwave, large-scale-structure, Lyman-alpha, and spectral-distortion probes taken together. The index runs from 0.9819 at the largest tabulated scale through 0.9648 at the pivot to 0.9604 at k = 2 per megaparsec and 0.9628 at k = 50 per megaparsec. The total variation across the table is 0.02149, which is 5.1 times the Planck uncertainty on the pivot index. The spectrum is therefore not describable by a constant index beyond the microwave window: analyses that extrapolate the pivot index to small scales would misestimate the index there by several times the pivot's own error bar. The tabulation provides the scale-by-scale values that joint analyses across probes require. The study is computed from stated assumptions, not measured.
Author: Aldred, William Alexander
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7225807596
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