{
"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"
}
}
}