Small scale clumps of dark matter

Abstract

®ÂÔÔ M min ÏÑAEÇÎßÐÑ-ÊÂÄËÔËÏÂ, ÒÓÇAEÔÍÂÊÞÄÂÇÏÂâ ÄÇÎËÚËРM min AEÎâ ÐÇÌÕÓÂÎËÐÑ Ä ®ËÐËÏÂÎßÐÑÌ ÔÖÒÇÓ-ÔËÏÏÇÕÓËÚÐÑÌ ÏÑAEÇÎË ÏÑÉÇÕ ËÊÏÇÐâÕßÔâ ÑÕ 10 À11 M AEÑ 10 À3 M [41,42,46,58,59]. ®ËÐËÏÂÎßÐÂâ ÏÂÔÔ ÔÅÖÔÕÍÑÄ (ÑÃÓÇÊÂÐËÇ ÔÒÇÍÕÓ ÏÂÔÔ) M min ÑÒÓÇAEÇÎâÇÕÔâ ÔÕÑÎÍÐÑÄË- ØÂÓÂÍÕÇÓËÊÖÇÕÔâ ÔÒÇÍÕÓÑÏ ÏÑÜÐÑÔÕË Pk: ÔÏ., ÐÂÒÓËÏÇÓ, [89, 90]). ¥Îâ ÏÇÎÍÑÏÂÔÛÕÂÃÐÞØ ÏÑAE Ô ÎÑÅÂÓË×ÏËÚÇÔÍÑÌ ÕÑÚ-ÐÑÔÕßá ÔÒÓÂÄÇAEÎËÄÑ ÔÑÑÕÐÑÛÇÐËÇ Tk 9 k eq ak 2 , ÇÔÎË k eq ak 5 1. ³ÓÇAEÐËÌ ÍÄÂAEÓÂÕ ÄÑÊÏÖÜÇÐËâ sR hd 2 i Ä ÏÂÔÛÕÂÃÇ R ÄÞÓÂÉÂÇÕÔâ ÚÇÓÇÊ Pk ÔÎÇAEÖáÜËÏ ÑÃÓÂÊÑÏ: £ËAEÐÑ, ÚÕÑ ÒÓË n s % Tam w p . ±ÖÔÕß dp ì ËÏÒÖÎßÔ, ÒÓËÑÃÓÇÕÂÇÏÞÌ ÐÇÌÕÓÂÎËÐÑ Ä ÑAEÐÑÏ ÓÂÔÔÇâÐËË: dp 2 2o 2 1 À cos y, ÅAEÇ o Ë y ì ÔÑÑÕÄÇÕÔÕÄÇÐÐÑ àÐÇÓÅËâ Ë ÖÅÑÎ ÓÂÔÔÇâÐËâ ×ÇÓÏËÑÐÂ.´ÑÅAE AEÎâ ÄÓÇÏÇÐË ÓÇÎÂÍÔÂÙËË t rel ÏÑÉÐÑ ÊÂÒËÔÂÕß ÅAEÇ f 1 9 0Y2À0Y3. ³ ÍÂÚÇÔÕÄÇÐÐÑÌ ÕÑÚÍË ÊÓÇÐËâ, ÒÇÓÄÞÌ ÏÐÑÉËÕÇÎß n Ä (88) ÔÑÑÕÄÇÕÔÕÄÖÇÕ ÕÑÏÖ ×ÂÍÕÖ, ÚÕÑ ÔÅÖÔÕÍË, ÑÃÓÂÊÑÄÂÄ-ÛËÇÔâ ËÊ ÄÞÔÑÍËØ ÒËÍÑÄ (Ô ÃÑÎßÛÇÌ ÄÇÎËÚËÐÑÌ n), ÖÔÒÇÛ-ÐÇÇ ÒÇÓÇÉËÄÂáÕ ÒÓÑÙÇÔÔÞ ÓÂÊÓÖÛÇÐËâ, ÚÇÏ ÔÅÖÔÕÍË, ÑÃÓÂÊÑÄÂÄÛËÇÔâ ËÊ ÐËÊÍËØ ÒËÍÑÄ (Ô ÏÇÐßÛËÏ n). ªÐÕÇÅ-ÓËÓÖâ (88) ÒÑ n, ÒÑÎÖÚÂÇÏ £ ÒÓÇAEÒÑÎÑÉÇÐËË, ÚÕÑ ÍÑÐÙÇÐÕÓÂÙËâ ÔÅÖÔÕÍÑÄ ÒÓÑ-ÒÑÓÙËÑÐÂÎßРÒÎÑÕÐÑÔÕË ÅÂÎÑ, Õ.Ç. n cl l xr DM l aM, AEÎâ ÍÑà××ËÙËÇÐÕ ÖÔËÎÇÐËâ ÒÑÎÖÚÂÇÏ ÖAEÑÃÐÖá ÑÙÇÐÍÖ: (2003) [JETP Lett. 77 335 (2003) Small scale clumps of dark matter are gravitationally bounded structures that have masses comparable to or lower than stellar masses and consist of non-or weakly interacting dark matter particles. In this paper the current knowledge of how such structures form and evolve is reviewed, various types of spectra of primordial cosmological perturbations are considered, and various dark matter models are examined. Depending on the particular spectrum type, dark matter clumps may differ considerably in their formation processes and ultimate characteristics. The role of clumps in experiments on dark matter particles indirect detection via their annihilation products is discussed. A number of astrophysical problems and phenomena that are related to dark matter clumps are examined.PACS numbers: 14.80. Nb, 95.35.+d, 98.70.Rz

Tidal streams from axion miniclusters and direct axion searches

“…These processes were studied by many authors, for a review see [7]. The axion miniclusters are too dense to be disrupted by the halo gravitational field.…”

“…For minihalos with M ∼ 10 −6 M their density in the Solar neighborhood after formation was found to be ∼ 500 pc −3 , the direct encounter with the Earth would occur once in 10 4 years, and during the encounter the DM density would increase by a factor of 100 over the average for about 50 years. However, virtually all minihalos which are crossing Solar neighborhood are tidally destroyed long before the present epoch [7,[9][10][11][12] producing a density field not interesting for the direct detection of DM [13]. The situation may be different for axion miniclusters due to an additional, different formation mechanism that leads to smaller and denser clumps, the axion miniclusters.…”

“…In any cold dark matter model (including WIMPs and axions) halos are formed, by a standard gravitational instability, on all scales from galaxies down to a free-streaming scale, leading to structure formation from primordial density perturbations. In case of WIMPs, the smallest halos have masses around M ∼ 10 −7 M as set by the free streaming scale in a typical WIMP model [5][6][7]. For the axion DM the minihalos form down to even smaller masses M ∼ 10 −12 M , which is the mass of all axions inside the horizon at the epoch when the axion oscillations commence.…”

Isocurvature Perturbation of Weakly Interacting Massive Particles and Small Scale Structure

“…They can be also the sources of neutrinos [24], detectable by IceCube [25]. Furthermore they can leave an imprint in the CMB by changing the reionization history of the Universe [26], produce a microlensing light curve [27,28], or change the direct detection rate [29].…”

R-parity violating supersymmetry at IceCube

“…Any of these 27 new dimensionless complex parameters can lead to resonant production of TeV-scale squarks at IceCube energies [68], thereby making a potentially significant contri-bution to the UHE neutrino events. Note that even without SUSY, similar resonance features in neutrino-nucleon interactions can also occur in models with TeV-scale leptoquarks [69][70][71][72][73][74][75]. 1 The λ-couplings in Eq.…”