Year: 2026
Type: preprint
Abstract: We use the Cross-Tracer Clustering Ratio (CTCR) acoustic response estimator, a new probe of morphology-dependent galaxy clustering in photometric surveys. CTCR is the ratio of the auto-power spectrum of early-type galaxies (ETGs) to their cross-power spectrum with late-type galaxies (LTGs). In the matched-kernel deterministic linear-bias limit the CTCR cancels the complete projected matter spectrum, including the baryon acoustic oscillation (BAO) wiggles, leaving only the relative linear bias. This makes the ratio uniquely sensitive to physics beyond deterministic linear bias: any residual acoustic structure in the CTCR must arise from a difference between the normalised non-linear responses of the two tracers. We, for the first time, exploit this property to model the measured ratio as a smooth scale-dependent baseline multiplied by a scale-dependent acoustic template, and constrain the amplitude $A_{\rm morph}$ of the differential acoustic response jointly with the BAO dilation parameter $α$. Applying the estimator to nine bins of the DESI Legacy Survey Data Release 8 spanning $0.1 < z < 0.9$, we obtain$α= 0.9997 \pm 0.0383$, consistent with the Planck 2018 $Λ$CDM prediction, and $A_{\rm morph} = 0.369 \pm 0.307$, consistent with zero. A Bayesian model comparison yields at most a 2.6$σ$ preference for the acoustic template over a smooth-only baseline. The estimator is model-independent, requires no external calibration of the absolute bias, and is directly applicable to the wide-field imaging surveys that will define the next decade of cosmology. It offers a new route to testing halo occupation and assembly-bias models, and an independent, systematics-robust cross-check of BAO measurements from spectroscopic surveys.
Source: arXiv (Cornell University)
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, University of Pennsylvania, Ohio State University, California Institute of Technology, University of Chicago, University of Portsmouth, University College London, University of Sussex, Deutsche Forschungsgemeinschaft, Chinese Academy of Sciences, Generalitat de Catalunya, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Financiadora de Estudos e Projetos, Zhejiang University, Institut de Física d'Altes Energies, University of Illinois at Urbana-Champaign, Office of Science, Jet Propulsion Laboratory, Science and Technology Facilities Council, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Agencia Estatal de Investigación, National Key Research and Development Program of China, Division of Astronomical Sciences, High Energy Physics, Integrated Electronics Engineering Center, Binghamton University, Argonne National Laboratory, Fermilab, Lawrence Berkeley National Laboratory, SLAC National Accelerator Laboratory
Awards: G1039895795, G1222680896, G1313983767, G1800429324, G1813527838, G2064873908, G2462415295, G272672434, G2988934680, G3005324705, G3204085874, G3418218065, G3452655474, G3546882995, G3753230853, G387521742, G4728539003, G498139845, G5180915604, G5608897973, G5779771523, G5922099756, G6027777510, G6876926712, G69051668, Management and Operations of the National Optical Astronomy Observatory, G7406122311, G7496233463, G7924537265, G8140570188, G8257951253, G863151887, G8836406373, G988696487
OpenAlex ID: W7223036007