@article{TEXTUAL,
      recid = {14515},
      author = {Sun, Yitian and Foster, Joshua W. and Liu, Hongwan and  Muñoz, Julian B. and Slatyer, Tracy R.},
      title = {Inhomogeneous energy injection in the 21-cm power  spectrum: Sensitivity to dark matter decay},
      journal = {Physical Review D},
      address = {2025-02-06},
      number = {TEXTUAL},
      abstract = {The 21-cm signal provides a novel avenue to measure the  thermal state of the Universe during cosmic dawn and  reionization (redshifts $𝑧∼5–30$), and thus to probe energy  injection from decaying or annihilating dark matter (DM).  These DM processes are inherently inhomogeneous: both decay  and annihilation are density-dependent, and furthermore,  the fraction of injected energy that is deposited at each  point depends on the gas ionization and density, leading to  further anisotropies in absorption and propagation. In this  work, we develop a new framework for modeling the impact of  spatially inhomogeneous energy injection and deposition  during cosmic dawn, accounting for ionization and baryon  density dependence, as well as the attenuation of  propagating photons. We showcase how this first completely  inhomogeneous treatment affects the predicted 21-cm power  spectrum in the presence of exotic sources of energy  injection, and forecast the constraints that upcoming HERA  measurements of the 21-cm power spectrum will set on DM  decays to photons and to electron/positron pairs. These  projected constraints considerably surpass those derived  from CMB and Lyman-𝛼 measurements, and for decays to  electron/positron pairs they exceed all existing  constraints in the sub-GeV mass range, reaching lifetimes  of $∼10^{28}$  s. Our analysis demonstrates the  unprecedented sensitivity of 21-cm cosmology to exotic  sources of energy injection during the cosmic dark ages.  Our code, dm21cm, includes all these effects and is  publicly available in an accompanying release.},
      url = {http://knowledge.uchicago.edu/record/14515},
}