Particle models and the small-scale structure of dark matter

By T. Bringmann. 2009

226 citations recorded by the source corpus.

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 underlying WIMP microphysics. With decoupling temperatures of several MeV to a few GeV, the smallest protohalos to be formed range between 10-11 and almost 10-3 solar masses—a somewhat smaller range than what was found earlier using order-of-magnitude estimates for the decoupling temperature; for a given WIMP model, the actual cutoff mass is typically about a factor of 10 greater than derived in that way, though in some cases the difference may be as large as a factor of several hundreds. Observational consequences and prospects to probe this small-scale cutoff, which would provide a fascinating new window into the particle nature of dark matter, are discussed.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/2d7b9f32cfc6fddedd0812f5616dd11f4ad67dd2

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Citations in the corpus

Characterization of subhalo structural properties and implications for dark matter annihilation signals (2016, background): “These processes depend on the particle physics and cosmological models (Profumo et al. 2006; Bringmann & Hofmann 2007; Bringmann 2009; van den Aarssen et al. 2012; Cornell & Profumo 2012; Gondolo et al. 2012; Cornell et al. 2013; Shoemaker 2013; Diamanti et al. 2015) and hence, the minimum mass is…”
ETHOS - an effective theory of structure formation: dark matter physics as a possible explanation of the small-scale CDM problems (2015, result): “The result is a much later kinetic decoupling of DM than in the standard case (Bringmann 2009), leading to cutoff scales of the primordial linear power spectrum that are on mass scales of order of dwarf galaxies and hence alleviate the overabundance problem of these (sub)halos in CDM cosmologies…”
Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects (2012, background): “lar that anisotropy measurements might turn out to be a feasible way to probe the minimal subhalo mass [157–160], which would open a completely complementary window into the particle nature of the DM [106]. 4. Current status 4.1. Limits The total number of photons above the detector threshold, typic”
Dark matter and fundamental physics with the Cherenkov Telescope Array (2012, background): “Theoretical models foresee a huge number of these substructures at all scales down to 10 11 10 3 M [101].”
Gravitational probes of dark matter physics (2017, background): “This occurs at a temperature Tkd, with the approximate relation [172, 173, 174, 175]”
Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background (2015, background): “Such a cut-off exists, for example, due to the free streaming length of DM particles after kinetic decoupling [28, 29], which gives the highest frequency relevant Fourier mode kmax.”
Numerical simulations of the dark universe: State of the art and the next decade (2012, background): “Given that the smallest collapsed structures in WIMP CDM are expected to be ∼ 10−12 − 10−3 M [129, 130], even the highest resolution numerical simulations can only resolve a small fraction of the expected substructure hierarchy.”