{
  "id": "1004.4167",
  "version": "v1",
  "published": "2010-04-23T15:54:01.000Z",
  "updated": "2010-04-23T15:54:01.000Z",
  "title": "Comments on Ultra-High-Energy Photons and D-Foam models",
  "authors": [
    "John Ellis",
    "Nick E. Mavromatos",
    "Dimitri V. Nanopoulos"
  ],
  "comment": "4 pages LaTeX",
  "categories": [
    "astro-ph.HE",
    "hep-ph"
  ],
  "abstract": "We revisit the constraints that the non-observation of ultra-high-energy photons due to the GZK cutoff can impose on models of Lorentz violation in photon propagation, following recent work by Maccione, Liberati and Sigl [arXiv:1003.5468] that carries further an earlier analysis by the present authors (Phys. Rev. D 63,12402 (2001), [hep-th/0012216]). We argue that the GZK cutoff constraint is naturally evaded in the D-brane model of space-time foam presented recently by the present authors (Phys. Lett. B 665, 412 (2008) [arXiv:0804.3566]), in which Lorentz-violating effects on photon propagation are independent of possible effects during interactions. We also note a novel absorption mechanism that could provide a GZK-like cutoff for photons in low-scale string models.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-04-23T15:54:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "ultra-high-energy photons",
      "d-foam models",
      "photon propagation",
      "gzk cutoff constraint",
      "novel absorption mechanism"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1016/j.physletb.2010.09.035",
      "journal": "Physics Letters B",
      "year": 2010,
      "month": "Oct",
      "volume": 694,
      "number": 1,
      "pages": 61
    },
    "note": {
      "typesetting": "LaTeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 852894,
      "adsabs": "2010PhLB..694...61E"
    }
  }
}