An anthropic solution to the cosmological moduli problem

Light moduli fields, gravitationally coupled scalar fields with no classical potential and which are expected to emerge as remnants from string theory compactification, dangerous cosmology in that 1. their late-time decays may disrupt successful Big Bang Nucleosynthesis (BBN), 2. they decay into gravitino pairs result violation of BBN constraints or overproduction lightest SUSY particles (LSPs, assumed constitute at least a portion the dark matter universe) 3. directly LSPs, resulting gross DM overproduction. Together, these cosmological problem (CMP). The combined effects require modulus mass mϕ≳104 TeV, if mϕ is correlated breaking scale m3/2, then underlying model would be highly unnatural. We present solution CMP wherein initial field strength ϕ0 anthropically selected ϕ0∼10−7mP by requirement matter-to-baryonic ratio not-too-far removed its value so sufficient baryons universe create observers. In this case, instead via neutralino reannihilation temperature, neutralinos inherit reduced number density, thereby gaining accord measured relic density.