DESI 2024 V: Full-Shape Galaxy Clustering from Galaxies and Quasars
Abstract
This technical note constrains a minimal, excitation-only late-time growth-response deformation around the GR-exact branch of the Gauged Constant Vacuum-Mode (GCV) programme. Using the public DESI DR1 6-bin ShapeFit growth compression, we test a single-parameter growth response model, in which the late-time growth amplitude may differ slightly from a GR-exact LCDM reference while the background expansion history remains unchanged. The response is parameterized by a single amplitude (epsilon) multiplying a fixed redshift-dependent response shape, calibrated on a GR-exact LCDM background for two illustrative profile choices. An analytic least-squares estimator is provided, together with goodness-of-fit statistics, allowing the constraint to be reproduced directly from the values reported in the note. The resulting constraint is compared to the UV-fixed production benchmarks PB1 and PB2, defined in the companion UV parameter-mapping package. Scope and limitation (explicit):This note intentionally uses a compact growth-compression interface and does not rerun the full DESI collaboration likelihood pipeline. It is intended as a reproducible, citable prediction/constraint card that can be upgraded in a follow-on likelihood-level analysis (v2.0.0). How to cite:Use the DOI and the "Cite as" line in the PDF header.