منابع مشابه
Small-scale structure of cold dark matter
We investigate the clumping of cold dark matter (CDM) at small scales. If the CDM particle is the neutralino, we find that collisional damping during its kinetic decoupling from the radiation fluid and free streaming introduce a small-scale cut-off in the primordial power spectrum of CDM. This cut-off sets the scale for the very first CDM objects in the Universe, which we expect to have a mass ...
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Hydrodynamic gravitational condensation theory and quasar-microlensing observations lead to the conclusion that the baryonic mass of most galaxies is dominated by dense clumps of hydrogenous planetoids. Star microlensing collaborations fail to detect planetoids as the dominant dark matter component of the inner Galaxy halo (within ≈ 30 kpc) by an unjustified uniformnumber-density assumption tha...
متن کاملLocal dark matter clumps and the positron excess
It has been proposed that the excess in cosmic ray positrons, at approximately 8GeV, observed on both flights of the HEAT balloon experiment may be associated with the annihilation of supersymmetric (SUSY) dark matter particles in the Milky Way halo. In this paper we show how the presence of local dark matter substructure could account for this excess. Specifically, we concentrate on dark matte...
متن کاملParticle Models and the Small-Scale Structure of Dark Matter
Abstract. The kinetic decoupling of weakly interacting massive particles (WIMPs) in the early universe sets a scale that can directly be translated into a small-scale cutoff in the spectrum of matter density fluctuations. The formalism presented here allows a precise description of the decoupling process and thus the determination of this scale to a high accuracy from the details of the underly...
متن کاملDecaying Cold Dark Matter Model and Small-scale Power
The canonical cosmological constant dominated cold dark matter model (ΛCDM ) may possess too much power on small scales at z = 0, manifested as central over-concentration of dark matter and over-abundance of dwarf galaxies. We suggest an alternative model, ΛDCDM, where one half of the cold dark matter particles decay into relativistic particles by z = 0. The model successfully lowers the concen...
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ژورنال
عنوان ژورنال: Physics-Uspekhi
سال: 2014
ISSN: 1063-7869,1468-4780
DOI: 10.3367/ufne.0184.201401a.0003