Dark Matter and Gravity Waves from a Dark Big Bang

Abstract

The Hot Big Bang is often considered as the origin of all matter and radiation in the Universe. Primordial nucleosynthesis (BBN) provides strong evidence that the early Universe contained a hot plasma of photons and baryons with a temperature $T>\text{MeV}$. However, the earliest probes of dark matter originate from much later times around the epoch of structure formation. In this work we describe a scenario in which dark matter (and possibly dark radiation) can be formed around or even after BBN in a second Big Bang which we dub the ``Dark Big Bang''. The latter occurs through a phase transition in the dark sector which transforms dark vacuum energy into a hot dark plasma of particles; in this paper we focus on a first-order phase transition for the Dark Big Bang. The correct dark matter abundance can be set by dark matter cannibalism or by pair-annihilation within the dark sector followed by a thermal freeze-out. Alternatively ultra-heavy ``dark-zilla'' dark matter can originate directly from bubble collisions during the Dark Big Bang. We will show that the Dark Big Bang is consistent with constraints from structure formation and the Cosmic Microwave Background (CMB) if it occurred when the Universe was less than one month old, corresponding to a temperature in the visible sector above $\mathcal{O}$(keV). While the dark matter evades direct and indirect detection, the Dark Big Bang gives rise to striking gravity wave signatures to be tested at pulsar timing array experiments. Furthermore, the Dark Big Bang allows for realizations of self-interacting and/or warm dark matter which suggest exciting discovery potential in future small-scale structure observations.

46 pages, 9 figures

References in corpus (24)

• Gauge Singlet Scalars as Cold Dark Matter
• Primordial Nucleosynthesis in the Precision Cosmology Era
• Gravitational Wave Production by Collisions: More Bubbles
• The Dawn of FIMP Dark Matter: A Review of Models and Constraints
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• Dark Matter and Dark Radiation
• Early dark energy, the Hubble-parameter tension, and the string axiverse
• The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background
• On the evidence for a common-spectrum process in the search for the nanohertz gravitational-wave background with the Parkes Pulsar Timing Array
• Gravitational wave generation from bubble collisions in first-order phase transitions: an analytic approach
• Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search
• Darkogenesis
• Thermal Dark Matter From A Highly Decoupled Sector
• How warm are non-thermal relics? Lyman-$\alpha$ bounds on out-of-equilibrium dark matter
• Probing the baryogenesis and dark matter relaxed in phase transition by gravitational waves and colliders
• Gravitational Waves from Hidden QCD Phase Transition
• Hot New Early Dark Energy
• Limiting First Order Phase Transitions in Dark Gauge Sectors from Gravitational Waves experiments
• Escape from supercooling with or without bubbles: gravitational wave signatures
• Reviving quark nuggets as a candidate for dark matter
• Have Pulsar Timing Arrays detected the Hot Big Bang? Gravitational Waves from Strong First Order Phase Transitions in the Early Universe
• Slow nucleation rates in Chain Inflation with QCD Axions or Monodromy
• The Thermal Abundance of Semi-Relativistic Relics
• The Power Spectrum of Density Perturbations in Chain Inflation