{
  "id": "2302.01331",
  "version": "v1",
  "published": "2023-02-02T18:59:19.000Z",
  "updated": "2023-02-02T18:59:19.000Z",
  "title": "Evidence for suppression of structure growth in the concordance cosmological model",
  "authors": [
    "Nhat-Minh Nguyen",
    "Dragan Huterer",
    "Yuewei Wen"
  ],
  "comment": "5 pages + references; 5 figures, 2 tables, 2900 words. Comments welcome!",
  "categories": [
    "astro-ph.CO",
    "gr-qc"
  ],
  "abstract": "We present evidence for a suppressed growth rate of large-scale structure during the dark-energy dominated era. Modeling the growth rate of perturbations with the ``growth index'' $\\gamma$, we find that current cosmological data strongly prefer a higher growth index than the value $\\gamma=0.55$ predicted by general relativity in a flat $\\Lambda$CDM cosmology. Both the cosmic microwave background data from Planck and the large-scale structure data from weak lensing, galaxy clustering, and cosmic velocities separately favor growth suppression. When combined, they yield $\\gamma=0.633^{+0.025}_{-0.024}$, excluding $\\gamma=0.55$ at a statistical significance of 3.7$\\sigma$. The combination of $f\\sigma_8$ and Planck measurements prefers an even higher growth index of $\\gamma=0.639^{+0.024}_{-0.025}$, corresponding to a 4.2$\\sigma$-tension with the concordance model. In Planck data, the suppressed growth rate offsets the preference for nonzero curvature and fits the data equally well as the latter model. A higher $\\gamma$ leads to a higher matter fluctuation amplitude $S_8$ inferred from galaxy clustering and weak lensing measurements, and a lower $S_8$ from Planck data, effectively resolving the $S_8$ tension.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-02-02T18:59:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "concordance cosmological model",
      "structure growth",
      "separately favor growth suppression",
      "velocities separately favor growth",
      "higher growth index"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}