Cosmology of atomic dark matter

By F. Cyr-Racine, K. Sigurdson. 2012

244 citations recorded by the source corpus.

While, to ensure successful cosmology, dark matter (DM) must kinematically decouple from the standard model plasma very early in the history of the Universe, it can remain coupled to a bath of "dark radiation" until a relatively late epoch. One minimal theory that realizes such a scenario is the Atomic Dark Matter model, in which two fermions oppositely charged under a new U(1) dark force are initially coupled to a thermal bath of "dark photons" but eventually recombine into neutral atom-like bound states and begin forming gravitationally-bound structures. As dark atoms have (dark) atom-sized geometric cross sections, this model also provides an example of self-interacting DM with a velocity-dependent cross section. Delayed kinetic decoupling in this scenario predicts novel DM properties on small scales but retains the success of cold DM on larger scales. We calculate the atomic physics necessary to capture the thermal history of this dark sector and show significant improvements over the standard atomic hydrogen calculation are needed. We solve the Boltzmann equations that govern the evolution of cosmological fluctuations in this model and find in detail the impact of the atomic DM scenario on the matter power spectrum and the cosmic microwave background (CMB). This scenario imprints a new length scale, the Dark-Acoustic-Oscillation (DAO) scale, on the matter density field. This DAO scale shapes the small-scale matter power spectrum and determines the minimal DM halo mass at late times which may be many orders of magnitude larger than in a typical WIMP scenario. This model necessarily includes an extra dark radiation component, which may be favoured by current CMB experiments, and we quantify CMB signatures that distinguish an atomic DM scenario from a standard $\Lambda$CDM model containing extra free-streaming particles. [Abridged]

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/62edde7e26b9fe7dabd6260d673fcadf6132a32c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Cosmological implications of Dark Matter bound states (2017, background): “So far, bound-state effects have mostly been considered in models of Dark Matter charged under a speculative abelian extra ‘dark force’, see [12] and references therein.”
Dwarf galaxies in CDM and SIDM with baryons: observational probes of the nature of dark matter (2014, background): “…new force carriers in a hidden DM sector (e.g. ArkaniHamed et al. 2009; Feng et al. 2009; Feng, Kaplinghat & Yu 2010; van den Aarssen, Bringmann & Pfrommer 2012; Cyr-Racine & Sigurdson 2013; Tulin, Yu & Zurek 2013; Cline et al. 2014), which predict velocity-dependent self-scattering cross-sections.”
New physics in light of the H0 tension: An alternative view (2019, unknown): “[248–266] for examples of such models.”
Dark matter models and direct detection (2019, background): “Another example is atomic dark matter [77], where the dark sector consists of a dark proton, a dark electron, and a dark photon; an example matter power spectrum was shown Fig.”
ETHOS - an effective theory of structure formation: dark matter physics as a possible explanation of the small-scale CDM problems (2015, background): “Depending on the detailed particle physics model, the power spectrum can have some nontrivial features like dark acoustic oscillations (DAOs) and a Silk damping tail (e.g. Buckley et al. 2014), which are a general phenomena of e.g. atomic dark matter models (e.g. Cyr-Racine & Sigurdson 2013).”
Dark nuclei. I. Cosmology and indirect detection (2014, background): “Popular examples include dark sectors, or sub-sectors, with dark atomic behavior [1–12] or strongly-coupled dark sectors leading to composite DM candidates [13–35], which are the focus of this work.”
CMB-S4 Science Case, Reference Design, and Project Plan (2019, background): “New light particles may arise in the form of axions and sterile neutrinos, or can appear as a byproduct of new symmteries that would explain the small mass of the Higgs boson [142, 143, 144, 145, 146, 147, 148, 10, 149, 150, 151, 152, 11, 153, 154, 141, 155, 12, 156, 157, 158, 159].”
Gravitational probes of dark matter physics (2017, background): “Such deviations can occur if the SIDM model contains a relatively light force carrier, such as the dark photon discussed in the previous section [37, 192, 193, 39] or dark pion from a confining sector [194].”
Colliding clusters and dark matter self-interactions (2013, background): “Such longrange interactions arise naturally in models of mirror DM (Blinnikov & Khlopov 1983; Kolb, Seckel & Turner 1985; Berezhiani, Dolgov & Mohapatra 1996; Foot 2004) or atomic DM (Kaplan et al. 2010; Cline, Liu & Xue 2012; Cyr-Racine & Sigurdson 2013).”