Cannibalism's lingering imprint on the matter power spectrum

Abstract

The early universe may have contained internally thermalized dark sectors that were decoupled from the Standard Model. In such scenarios, the relic dark thermal bath, composed of the lightest particle in the dark sector, can give rise to an epoch of early matter domination prior to Big Bang Nucleosynthesis, which has a potentially observable impact on the smallest dark matter structures. This lightest dark particle can easily and generically have number-changing self-interactions that give rise to "cannibal" behavior. We consider cosmologies where an initially sub-dominant cannibal species comes to temporarily drive the expansion of the universe, and we provide a simple map between the particle properties of the cannibal species and the key features of the enhanced dark matter perturbation growth in such cosmologies. We further demonstrate that cannibal self-interactions can determine the small-scale cutoff in the matter power spectrum even when the cannibal self-interactions freeze out prior to cannibal domination.

38 pages + 11 pages appendices, and 9 figures; Corrected expression for cannibal cross section; results unchanged

References in corpus (17)

• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Effects of cold dark matter decoupling and pair annihilation on cosmological perturbations
• Thermal Dark Matter From A Highly Decoupled Sector
• Pulsar Timing Probes of Primordial Black Holes and Subhalos
• Co-Decaying Dark Matter
• SIMPle Dark Matter: Self-Interactions and keV Lines
• Non-thermal Histories and Implications for Structure Formation
• Heating in Brane Inflation and Hidden Dark Matter
• Imprints of the Early Universe on Axion Dark Matter Substructure
• Superdense cosmological dark matter clumps
• Predicting the density profiles of the first halos
• Breaking a dark degeneracy: The gamma-ray signature of early matter domination
• Long-lived Light Mediator to Dark Matter and Primordial Small Scale Spectrum
• Bayesian Forecasts for Dark Matter Substructure Searches with Mock Pulsar Timing Data
• On Axion Reheating in the String Landscape
• Smallest Remnants of Early Matter Domination
• Dark Matter Microhalos in the Solar Neighborhood: Pulsar Timing Signatures of Early Matter Domination

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• Cannibal dark matter decoupled from standard model: cosmological constraints
• Simulations of Gravitational Heating Due to Early Matter Domination
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• How an era of kination impacts substructure and the dark matter annihilation rate
• Early Growth of Structure in Warm Wave Dark Matter
• 21-cm Constraints on Dark Matter Annihilation after an Early Matter-Dominated Era
• Gravothermalizing into primordial black holes, boson stars, and cannibal stars
• Using Gravitational Wave Signals to Disentangle Early Matter Dominated Epochs
• Limits on Early Matter Domination from the Isotropic Gamma-Ray Background
• Structure Formation with Warm White Noise: Effects of Finite Number Density and Velocity Dispersion in Particle and Wave Dark Matter
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• Bispectrum of induced gravitational waves in the poltergeist mechanism