{
  "id": "1711.10867",
  "version": "v1",
  "published": "2017-11-29T14:18:01.000Z",
  "updated": "2017-11-29T14:18:01.000Z",
  "title": "Testing Modified Gravity Theories via Wide Binaries and GAIA",
  "authors": [
    "Charalambos Pittordis",
    "Will Sutherland"
  ],
  "comment": "LaTeX, 18 pages, 14 figures. Submitted to MNRAS",
  "categories": [
    "astro-ph.CO",
    "gr-qc"
  ],
  "abstract": "The standard LambdaCDM model based on General Relativity (GR) including cold dark matter (CDM) is very successful at fitting cosmological observations, but recent non-detections of candidate dark matter (DM) particles mean that various modified-gravity theories remain of significant interest. The latter generally involve modifications to GR below a critical acceleration scale $\\sim 10^{-10} \\, m \\, s^{-2}$. Wide-binary (WB) star systems with separations $> 5 \\, kAU$ provide an interesting test for modified gravity, due to being in or near the low-acceleration regime and presumably containing negligible DM. Here, we explore the prospects for new observations pending from the GAIA spacecraft to provide tests of GR against MOND or TeVes-like theories in a new and relatively untested regime. In particular, we find that a histogram of (3D) binary relative velocities against circular velocity predicted from the (2D) projected separations predicts a rather sharp feature in this distribution for standard gravity, with an 80th (90th) percentile value close to 1.025 (1.14) with rather weak dependence on the eccentricity distribution. However, MOND/TeVeS theories produce a shifted distribution, with a significant increase in these upper percentiles. In MOND-like theories {\\em without} an external field effect, there are large shifts of order unity. With the external field effect included, the shifts are considerably reduced to $\\sim 0.04 - 0.08$, but are still potentially detectable statistically given reasonably large samples and good control of contaminants. In principle, followup of GAIA-selected wide binaries with ground-based radial velocities accurate to < 0.03 km/s should be able to produce an interesting new constraint on modified-gravity theories.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-11-29T14:18:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "testing modified gravity theories",
      "wide binaries",
      "external field effect",
      "modified-gravity theories",
      "radial velocities accurate"
    ],
    "note": {
      "typesetting": "LaTeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}