Multiverse Dark Matter: SUSY or Axions

Abstract

The observed values of the cosmological constant {\it and} the abundance of Dark Matter (DM) can be successfully understood, using certain measures, by imposing the anthropic requirement that density perturbations go non-linear and virialize to form halos. This requires a probability distribution favoring low amounts of DM, i.e. low values of the PQ scale $f$ for the QCD axion and low values of the superpartner mass scale $\tilde{m}$ for LSP thermal relics. In theories with independent scanning of multiple DM components, there is a high probability for DM to be dominated by a single component. For example, with independent scanning of $f$ and $\tilde{m}$, TeV-scale LSP DM and an axion solution to the strong CP problem are unlikely to coexist. With thermal LSP DM, the scheme allows an understanding of a Little SUSY Hierarchy with multi-TeV superpartners. Alternatively, with axion DM, PQ breaking before (after) inflation leads to $f$ typically below (below) the projected range of the current ADMX experiment of $f=(3-30)\times 10^{11}$ GeV, providing strong motivation to develop experimental techniques for probing lower $f$.

32 pages, 14 figures, version published on JHEP

References in corpus (4)

• Resonant detection of axion mediated forces with Nuclear Magnetic Resonance
• Holographic probabilities in eternal inflation
• Limiting P-odd interactions of cosmic fields with electrons, protons and neutrons
• A geometric solution to the coincidence problem, and the size of the landscape as the origin of hierarchy

Cited by in corpus (5)

• The photo-philic QCD axion
• Thermal QCD Axions across Thresholds
• Dark Matter in $\gamma$ lines: Galactic Center vs dwarf galaxies
• Observable dark radiation from cosmologically safe QCD axion
• Radiative PQ Breaking and the Higgs Boson Mass