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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The 21-cm signal provides a novel avenue to measure the thermal state of theuniverse during cosmic dawn and reionization (redshifts $z\sim 5-30$), and thusto probe energy injection from decaying or annihilating dark matter (DM). TheseDM processes are inherently inhomogeneous: both decay and annihilation aredensity dependent, and furthermore the fraction of injected energy that isdeposited at each point depends on the gas ionization and density, leading tofurther anisotropies in absorption and propagation. In this work, we develop anew framework for modeling the impact of spatially inhomogeneous energyinjection and deposition during cosmic dawn, accounting for ionization andbaryon density dependence, as well as the attenuation of propagating photons.We showcase how this first completely inhomogeneous treatment affects thepredicted 21-cm power spectrum in the presence of exotic sources of energyinjection, and forecast the constraints that upcoming HERA measurements of the21-cm power spectrum will set on DM decays to photons and to electron/positronpairs. These projected constraints considerably surpass those derived from CMBand Lyman-$\alpha$ measurements, and for decays to electron/positron pairs theyexceed all existing constraints in the sub-GeV mass range, reaching lifetimesof $\sim 10^{28}\,\mathrm{s}$. Our analysis demonstrates the unprecedentedsensitivity of 21-cm cosmology to exotic sources of energy injection during thecosmic dark ages. Our code, $\mathtt{DM21cm}$, includes all these effects andis publicly available in an accompanying release.

Inhomogeneous Energy Injection in the 21-cm Power Spectrum: Sensitivity to Dark Matter Decay