The Dark Matter Annihilation Boost from Low-Temperature Reheating

Abstract

The evolution of the Universe between inflation and the onset of big bang nucleosynthesis is difficult to probe and largely unconstrained. This ignorance profoundly limits our understanding of dark matter: we cannot calculate its thermal relic abundance without knowing when the Universe became radiation dominated. Fortunately, small-scale density perturbations provide a probe of the early Universe that could break this degeneracy. If dark matter is a thermal relic, density perturbations that enter the horizon during an early matter-dominated era grow linearly with the scale factor prior to reheating. The resulting abundance of substructure boosts the annihilation rate by several orders of magnitude, which can compensate for the smaller annihilation cross sections that are required to generate the observed dark matter density in these scenarios. In particular, thermal relics with masses less than a TeV that thermally and kinetically decouple prior to reheating may already be ruled out by Fermi-LAT observations of dwarf spheroidal galaxies. Although these constraints are subject to uncertainties regarding the internal structure of the microhalos that form from the enhanced perturbations, they open up the possibility of using gamma-ray observations to learn about the reheating of the Universe.

26 pages, 15 figures; minor changes made to match published version

References in corpus (33)

• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• Reheating in Inflationary Cosmology: Theory and Applications
• Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Neutralino with the Right Cold Dark Matter Abundance in (Almost) Any Supersymmetric Model
• Reheating constraints to inflationary models
• Hylogenesis: A Unified Origin for Baryonic Visible Matter and Antibaryonic Dark Matter
• What mass are the smallest protohalos?
• Effects of cold dark matter decoupling and pair annihilation on cosmological perturbations
• Search for Gamma-Ray Emission from DES Dwarf Spheroidal Galaxy Candidates with Fermi-LAT Data
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• Cosmological Moduli and the Post-Inflationary Universe: A Critical Review
• The effect of a late decaying scalar on the neutralino relic density
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• Hierarchical Formation of Dark Matter Halos and the Free Streaming Scale
• The survival and disruption of CDM micro-haloes: implications for direct and indirect detection experiments
• Galactic Substructure and Dark Matter Annihilation in the Milky Way Halo
• Search for dark matter annihilation signatures in H.E.S.S. observations of Dwarf Spheroidal Galaxies
• Non-thermal Histories and Implications for Structure Formation
• Collapse of Small-Scale Density Perturbations during Preheating in Single Field Inflation
• Small-scale clumps of dark matter
• Axion constraints in non-standard thermal histories
• Generation of gravitational waves during early structure formation between cosmic inflation and reheating
• On mini-halo encounters with stars
• Ultra-cold WIMPs: relics of non-standard pre-BBN cosmologies
• Constraint on the Effective Number of Neutrino Species from the WMAP and SDSS LRG Power Spectra
• Abundance of Cosmological Relics in Low-Temperature Scenarios
• Superdense cosmological dark matter clumps
• Long-lived Light Mediator to Dark Matter and Primordial Small Scale Spectrum
• Evolution of Characteristic Quantities for Dark Matter Halo Density Profiles
• Neutralino and gravitino dark matter with low reheating temperature
• On finite density effects on cosmic reheating and moduli decay and implications for Dark Matter production
• Neutralino Dark Matter and the Curvaton

Cited by in corpus (69)

• WIMP dark matter candidates and searches - current status and future prospects
• The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
• Parametric Resonance Production of Ultralight Vector Dark Matter
• Probing the pre-BBN universe with gravitational waves from cosmic strings
• Gravitational probes of dark matter physics
• Phase Transitions in an Expanding Universe: Stochastic Gravitational Waves in Standard and Non-Standard Histories
• Cannibal Dark Matter
• Mechanisms for Primordial Black Hole Production in String Theory
• Density profiles of ultracompact minihalos: Implications for constraining the primordial power spectrum
• Homeopathic Dark Matter, or how diluted heavy substances produce high energy cosmic rays
• Core-collapse, evaporation and tidal effects: the life story of a self-interacting dark matter subhalo
• Simulations of Axion Minihalos
• Axion Cosmology with Early Matter Domination
• Concentrated Dark Matter: Enhanced Small-scale Structure from Co-Decaying Dark Matter
• Primordial Black Hole Archaeology with Gravitational Waves from Cosmic Strings
• Neutrino Portal to FIMP Dark Matter with an Early Matter Era
• Connecting CMB anisotropy and cold dark matter phenomenology via reheating
• (Non-)thermal production of WIMPs during kination
• The Abundance and Structure of Subhaloes near the Free Streaming Scale and Their Impact on Indirect Dark Matter Searches
• Predicting the density profiles of the first halos
• Annihilation Signatures of Hidden Sector Dark Matter Within Early-Forming Microhalos
• Growth of Dark Matter Perturbations during Kination
• Breaking a dark degeneracy: The gamma-ray signature of early matter domination
• New Constraints on Dark Matter Production during Kination
• Dark Matter Microhalos From Simplified Models
• Bringing Isolated Dark Matter Out of Isolation: Late-time Reheating and Indirect Detection
• Neutralino Dark Matter in Scenarios with Early Matter Domination
• The Inflaton Portal to a Highly decoupled EeV Dark Matter Particle
• Non-thermal WIMPs and Primordial Black Holes
• Evolution of dark matter microhalos through stellar encounters
• Tidal evolution of dark matter annihilation rates in subhalos
• Neutrino masses and superheavy dark matter in the 3-3-1-1 model
• Cannibal domination and the matter power spectrum
• Stasis in an Expanding Universe: A Recipe for Stable Mixed-Component Cosmological Eras
• Constraints on Dark Matter from Dynamical Heating of Stars in Ultrafaint Dwarfs. Part 2: Substructure and the Primordial Power Spectrum
• Constraining Nonthermal Dark Matter's Impact on the Matter Power Spectrum
• Constraining Non-thermal Dark Matter by CMB
• Cannibalism's lingering imprint on the matter power spectrum
• Quasidecoupled state for dark matter in nonstandard thermal histories
• Non-thermal Dark Matter from Modified Early Matter Domination
• Cosmology in the presence of multiple light moduli
• Dark Matter Microhalos in the Solar Neighborhood: Pulsar Timing Signatures of Early Matter Domination
• Dynamical Dark Matter from Thermal Freeze-Out
• Freeze-in Production of Dark Matter Prior to Early Matter Domination
• Superheavy Dark Matter from String Theory
• Early Matter Domination from Long-Lived Particles in the Visible Sector
• Boosting small-scale structure via primordial black holes and implications for sub-GeV dark matter annihilation
• A new bound on the low reheating temperature with dark matter
• The Effects Of Relativistic Hidden Sector Particles on the Matter Power Spectrum
• Solar Mass Primordial Black Holes in Moduli Dominated Universe
• Gravitational Wave Symphony from Oscillating Spectator Scalar Fields
• A map of the non-thermal WIMP
• How an era of kination impacts substructure and the dark matter annihilation rate
• Simulations of Gravitational Heating Due to Early Matter Domination
• Dark Matter and Baryogenesis from Visible-Sector Long-Lived Particles
• Comment on "Kinetic decoupling of WIMPs: Analytic expressions"
• Visualizing Invisible Dark Matter Annihilation with the CMB and Matter Power Spectrum
• 21-cm Constraints on Dark Matter Annihilation after an Early Matter-Dominated Era
• Hidden Sector Monopole Dark Matter with Matter Domination
• Dark matter cooling during early matter-domination boosts sub-earth halos
• The cusp-halo relation
• Limits on Early Matter Domination from the Isotropic Gamma-Ray Background
• Cosmology of Single Species Hidden Dark Matter
• Anomalous EDGES 21-cm Signal and Moduli Dominated Era
• CMB lensing from early-formed dark matter halos
• Impact of a Rapid Diluted Energy Density on the halo mass function
• Imprints of an early matter-dominated era arising from dark matter dilution mechanism on cosmic string dynamics and gravitational wave signatures
• Dark matter from mediator decay in early matter domination
• Thermal History of the Universe After Inflation