Primordial Black Hole as a Source of the Boost Factor
arXiv:1009.1947 · doi:10.1016/j.physletb.2011.01.038
Abstract
Primordial black holes (PBHs) accumulate weakly interacting massive particles (WIMPs) around them and form ultracompact minihalos (UCMHs), if the WIMP is a dominant component of the dark matter (DM). In this paper, we discuss that the UCMHs seeded by the PBHs with sub-earth mass enhance the WIMP annihilation in the present Universe and can successfully explain the positron and/or electron excess in cosmic ray observed by PAMELA/Fermi experiments. The signal is very similar to that from a decaying dark matter, which can explain the PAMELA and/or Fermi anomaly without conflict with any constraints as long as the decay mode is proper. In this scenario, the boost factor can be as large as 10^5. In addition, we discuss testability of our scenario by gamma-ray point source and gravitational-wave experiments.
17 pages, 3 figure
References in corpus (15)
- Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
- Observation of an anomalous positron abundance in the cosmic radiation
- A Theory of Dark Matter
- Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
- The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
- Effect of Primordial Black Holes on the Cosmic Microwave Background and Cosmological Parameter Estimates
- Decaying Dark Matter can explain the electron/positron excesses
- Gamma-ray and radio tests of the e+e- excess from DM annihilations
- What mass are the smallest protohalos?
- PAMELA Positron Excess as a Signal from the Hidden Sector
- Contraints on radiative dark-matter decay from the cosmic microwave background
- The PAMELA and ATIC Excesses From a Nearby Clump of Neutralino Dark Matter
- Dark matter annihilation near a black hole: plateau vs. weak cusp
- Cosmic ray lepton puzzle in the light of cosmological N-body simulations
- The Status and future of ground-based TeV gamma-ray astronomy. A White Paper prepared for the Division of Astrophysics of the American Physical Society