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

We consider an inelastic dark matter model, where a fermion is charged undera broken U(1) gauge symmetry, and introduce a tiny Majorana mass term to splitthe fermion into two states with the light one being a dark matter candidate.If the gauge boson is light, it can mediate both elastic and inelastic darkmatter self-interactions in dark halos, leading to observational consequences.Using a numerical technique based on partial wave analysis, we accuratelycalculate the elastic and inelastic self-scattering cross sections. We assume athermal freeze-out scenario and fix the gauge coupling constant using the relicdensity constraint. Then, we focus on six benchmark masses of dark matter,covering a wide range from $10~{\rm MeV}$ to $160~{\rm GeV}$ and map parameterregions where the elastic scattering cross section per unit mass is within$1~{\rm cm^2/g} - 5~{\rm cm^2/g}$, favored to solve small-scale issues of colddark matter. If the heavy state can decay to the light state and a masslessspecies, the inelastic up-scattering process can cool the halo and lead to corecollapse. Taking galaxies with evidence of dark matter density cores, wefurther derive constraints on the parameter space. For dark matter masses below$10~{\rm GeV}$, the mass splitting must be large enough to forbid up scatteringin the dwarf halo for evading the core-collapse constraint; while for highermasses, the up-scattering process can still be allowed. Our results showastrophysical observations can provide powerful tests for dark matter modelswith large elastic and inelastic self-interactions.

Astrophysical probes of inelastic dark matter with a light mediator