English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In the last few years there has been some interest in WIMP Dark Matter modelsfeaturing a velocity dependent cross section through the Sommerfeld enhancementmechanism, which is a nonrelativistic effect due to massive bosons in the darksector. In the first part of this article, we find analytic expressions for theboost factor for three different model potentials, the Coulomb potential, thespherical well and the spherical cone well and compare with the numericalsolution of the Yukawa potential. We find that the resonance pattern of all thepotentials can be cast into the same universal form. In the second part of thearticle we perform a detailed computation of the Dark Matter relic density formodels having Sommerfeld enhancement by solving the Boltzmann equationnumerically. We calculate the expected distortions of the CMB blackbodyspectrum from WIMP annihilations and compare these to the bounds set by FIRAS.We conclude that only a small part of the parameter space can be ruled out bythe FIRAS observations.

Sommerfeld Enhancement of DM Annihilation: Resonance Structure, Freeze-Out and CMB Spectral Bound