| タイトル | Constraints on axions from the extragalactic background light |
| 著者（英） | Wesson, P. S.; Overduin, J. M. |
| 著者所属（英） | NASA Headquarters |
| 発行日 | 1993-09-10 |
| 言語 | eng |
| 内容記述 | We consider the effect of dark matter in the form of multi-eV axions on the extragalactic background light. Our treatment differs from that of other workers in that we assume axions to be clustered in Galactic halos, with nonzero velocity dispersions. We also approach the problem in a fully general relativistic manner, treating the axion halos as luminous elements of a pressure-free perfect fluid in a standard Friedmann-Robertson-Walker universe. We find that the ultraviolet extragalactic background light places a firm upper limit of 9 eV on the axion rest energy, and that this drops to 4 eV for the simplest axion models, all but closing the multi-eV axion window (which begins at 3 eV). These results are close to earlier upper limits of 5 and 8 eV derived from the extragalactic background by Turner and Ressell, respectively. Although our methods differ somewhat from theirs, our findings support their conclusion that axions, if they exist, are likely to have rest energies well below the eV range. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 93A56055 |
| 権利 | Copyright |
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