{
  "id": "1503.01122",
  "version": "v1",
  "published": "2015-03-03T21:00:18.000Z",
  "updated": "2015-03-03T21:00:18.000Z",
  "title": "On the luminosity distance and the epoch of acceleration",
  "authors": [
    "Will Sutherland",
    "Paul Rothnie"
  ],
  "comment": "Latex, 13 pages, 7 figures. Accepted by MNRAS. For the busy reader, Figs 4 and 6 are the main results",
  "journal": "MNRAS (2015), 446, 3863",
  "doi": "10.1093/mnras/stu2369",
  "categories": [
    "astro-ph.CO"
  ],
  "abstract": "Standard cosmological models based on general relativity (GR) with dark energy predict that the Universe underwent a transition from decelerating to accelerating expansion at a moderate redshift $z_{acc} \\sim 0.7$. Clearly, it is of great interest to directly measure this transition in a model-independent way, without the assumption that GR is the correct theory of gravity. We explore to what extent supernova (SN) luminosity distance measurements provide evidence for such a transition: we show that, contrary to intuition, the well-known \"turnover\" in the SN distance residuals $\\Delta\\mu$ relative to an empty (Milne) model does not give firm evidence for such a transition within the redshift range spanned by SN data. The observed turnover in that diagram is predominantly due to the negative curvature in the Milne model, {\\em not} the deceleration predicted by $\\Lambda$CDM and relatives. We show that there are several advantages in plotting distance residuals against a flat, non-accelerating model $(w = -1/3)$, and also remapping the $z-$axis to $u = \\ln(1+z)$; we outline a number of useful and intuitive properties of this presentation. We conclude that there are significant complementarities between SNe and baryon acoustic oscillations (BAOs): SNe offer high precision at low redshifts and give good constraints on the net {\\em amount} of acceleration since $z \\sim 0.7$, but are weak at constraining $z_{acc}$; while radial BAO measurements are probably superior for placing direct constraints on $z_{acc}$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-03-03T21:00:18.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "acceleration",
      "transition",
      "sne offer high precision",
      "baryon acoustic oscillations",
      "luminosity distance measurements"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "LaTeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1341691
    }
  }
}