CMB and 21-cm signals for dark matter with a long-lived excited state
![Thumbnail](/bitstream/handle/1/34469822/PhysRevD.78.063530.pdf.jpg?sequence=8&isAllowed=y)
View/ Open
Published Version
https://doi.org/10.1103/physrevd.78.063530Metadata
Show full item recordCitation
Finkbeiner, Douglas P., Nikhil Padmanabhan, and Neal Weiner. 2008. “CMB and 21-Cm Signals for Dark Matter with a Long-Lived Excited State.” Physical Review D 78 (6) (September 18). doi:10.1103/physrevd.78.063530. http://dx.doi.org/10.1103/physrevd.78.063530.Abstract
Motivated by the eXciting Dark Matter (XDM) model of Finkbeiner & Weiner, hypothesized to explain the 511 keV signal in the center of the Milky Way, we consider the CMB and 21-cm signatures of models of dark matter with collisional long-lived excited states. We compute the relic excitation fraction from the early universe for a variety of assumptions about the collisional de-excitation cross-section and thermal decoupling. The relic excitation fraction can be as high as 1% for natural regions of parameter space, but could be orders of magnitude smaller. Since the lifetime of the excited state is naturally greater than 10^13s, we discuss the signatures of such relic excitation on cosmic microwave background (CMB) and high-z 21-cm observations. Such models have potentially richer astrophysical signals than the traditional WIMP annihilations and decays, and may have observable consequences for future generations of experiments.Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:34469822
Collections
- FAS Scholarly Articles [18304]
Contact administrator regarding this item (to report mistakes or request changes)