Dark matter annihilation near a black hole: plateau vs. weak cusp
| dc.creator | Vasiliev, Eugene | |
| dc.date | 2007-07-23 | |
| dc.date | 2007-12-01 | |
| dc.date.accessioned | 2026-07-07T11:41:34Z | |
| dc.date.available | 2026-07-07T11:41:34Z | |
| dc.description | Dark matter annihilation in so-called ``spikes'' near black holes is believed to be an important method of indirect dark matter detection. In the case of circular particle orbits, the density profile of dark matter has a plateau at small radii, the maximal density being limited by the annihilation cross-section. However, in the general case of arbitrary velocity anisotropy the situation is different. Particulary, for isotropic velocity distribution the density profile cannot be shallower than r^{-1/2} in the very centre. Indeed, a detailed study reveals that in many cases the term ``annihilation plateau'' is misleading, as the density actually continues to rise towards small radii and forms a weak cusp, rho ~ r^{-(beta+1/2)}, where beta is the anisotropy coefficient. The annihilation flux, however, does not change much in the latter case, if averaged over an area larger than the annihilation radius. | |
| dc.description | 4 pages, 3 figures. Matches published version | |
| dc.identifier | https://arxiv.org/abs/0707.3334 | |
| dc.identifier | http://arxiv.org/abs/0707.3334 | |
| dc.identifier | Phys.Rev.D76:103532,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.103532 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/200576 | |
| dc.subject | Astrophysics | |
| dc.title | Dark matter annihilation near a black hole: plateau vs. weak cusp | |
| dc.type | text |