CMB constraints on WIMP annihilation: Energy absorption during the recombination epoch

By T. Slatyer, Nikhil Padmanabhan, Douglas P. Finkbeiner. 2009

412 citations recorded by the source corpus.

We compute in detail the rate at which energy injected by dark matter (DM) annihilation heats and ionizes the photon-baryon plasma at z{approx}1000, and provide accurate fitting functions over the relevant redshift range for a broad array of annihilation channels and DM masses. The resulting perturbations to the ionization history can be constrained by measurements of the CMB temperature and polarization angular power spectra. We show that models which fit recently measured excesses in 10-1000 GeV electron and positron cosmic rays are already close to the 95% confidence limits from WMAP. The recently launched Planck satellite will be capable of ruling out a wide range of DM explanations for these excesses. In models of dark matter with Sommerfeld-enhanced annihilation, where rises with decreasing WIMP velocity until some saturation point, the WMAP5 constraints imply that the enhancement must be close to saturation in the neighborhood of the Earth.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/b787e594808a904065d152d36a7839135f603318

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In Astronomy and Astrophysics

1. Marco Peloso
2. D. Baumann
3. Xingang Chen
4. H. Eriksen
5. K. G'orski
6. Florian Kuhnel
7. J. Chluba
8. Tongyan Lin

In Nuclear and High Energy Physics

1. Tongyan Lin
2. R. Essig
3. S. Profumo
4. Marco Peloso
5. D. Baumann
6. K. Zurek
7. J. Gaskins
8. Samuel D. McDermott

Citations in the corpus

• The effects of QCD equation of state on the relic density of WIMP dark matter (2015, methodology): “[64], we estimate that the latest PLANCK data exclude WIMPs with m < 40 GeV annihilating into e+e− pairs with temperature independent cross section; see also the recent analysis [65], which obtains the limit m < 50 GeV.”
• CMB at 2 × 2 order: the dissipation of primordial acoustic waves and the observable part of the associated energy release (2012, background): “…there is no additional source of photons other than BR and DC. Detailed calculations of the particle cascade caused by energy release in the form of decaying or annihilating relic particles (e.g., Slatyer et al. 2009) could allow the inclusion of additional processes that lead to photon production.”
• Cosmological Moduli and the Post-Inflationary Universe: A Critical Review (2015, background): “These constraints arise because energy injection from increased dark matter annihilation can alter the recombination history14 leading to changes in the temperature and polarization power spectra of the CMB [66].”
• Constraining light dark matter with diffuse X-ray and gamma-ray observations (2013, background): “Constraints from the Cosmic Microwave Background (CMB) already limit the s-wave DM annihilation cross section to SM matter to be below that of a thermal WIMP, for DM masses below ∼ 7 GeV [24–27].”
• Explaining dark matter and B decay anomalies with an Lμ − Lτ model (2016, background): “Specifically, dark matter annihilation at redshifts z ∼ 1000 results in energy injection which heats and ionizes the photon-baryon plasma, significantly perturbing the ionization history in a way that can be constrained by measurements of the CMB temperature and polarization angular power spectra [9”
• PICO: Probe of Inflation and Cosmic Origins (2019, background): “• Dark Matter CMB experiments are effective in constraining dark matter candidates in the lower mass range, which is not available for terrestrial direct detection experiments [7–12].”
• A review of indirect searches for particle dark matter (2016, background): “sion with observational bounds [155,210,239,254–258] anddistortions of theCMB[11,12],making it challenging”
• The evolution of CMB spectral distortions in the early Universe (2011, background): “This suggests that the bounds onfann derived from the CMB anisotropies (Slatyer et al. 2009; Galli et al. 2009; Hütsi et al. 2009, 2011) already now might be in tension with this heating mechanism, however, the energy release from acoustic waves only goes into heating of the medium, while for…”
• Background model systematics for the Fermi GeV excess (2014, background): “Finally, limits from observations of the cosmic microwave background constrain leptonic models for DM annihilation [135–139], though not at a level that is relevant for the GCE right now.”