{
  "id": "2308.16183",
  "version": "v1",
  "published": "2023-08-30T17:59:01.000Z",
  "updated": "2023-08-30T17:59:01.000Z",
  "title": "Late Time Modification of Structure Growth and the S8 Tension",
  "authors": [
    "Meng-Xiang Lin",
    "Bhuvnesh Jain",
    "Marco Raveri",
    "Eric J. Baxter",
    "Chihway Chang",
    "Marco Gatti",
    "Sujeong Lee",
    "Jessica Muir"
  ],
  "comment": "6 pages, 5 figures, 1 table",
  "categories": [
    "astro-ph.CO"
  ],
  "abstract": "The $S_8$ tension between low-redshift galaxy surveys and the primary CMB signals a possible breakdown of the $\\Lambda$CDM model. Recently differing results have been obtained using low-redshift galaxy surveys and the higher redshifts probed by CMB lensing, motivating a possible time-dependent modification to the growth of structure. We investigate a simple phenomenological model in which the growth of structure deviates from the $\\Lambda$CDM prediction at late times, in particular as a simple function of the dark energy density. Fitting to galaxy lensing, CMB lensing, BAO, and Supernovae datasets, we find significant evidence - 2.5 - 3$\\sigma$, depending on analysis choices - for a non-zero value of the parameter quantifying a deviation from $\\Lambda$CDM. The preferred model, which has a slower growth of structure below $z\\sim 1$, improves the joint fit to the data over $\\Lambda$CDM. While the overall fit is improved, there is weak evidence for galaxy and CMB lensing favoring different changes in the growth of structure.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-08-30T17:59:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "late time modification",
      "structure growth",
      "s8 tension",
      "low-redshift galaxy surveys",
      "cmb lensing"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}