Non-critical string cosmologies

摘要

Non-critical String Cosmologies are offered as an alternative to Standard Big Bang Cosmology. The new features encompassed within the dilaton dependent non-critical terms affect the dynamics of the Universes evolution in an unconventional manner being in agreement with the cosmological data. Non-criticality is responsible for a late transition to acceleration at redshifts z=0.2. The role of the uncoupled rolling dilaton to relic abundance calculations is discussed. The uncoupled rolling dilaton dilutes the neutralino relic densities in supersymmetric theories by factors of ten, relaxing considerably the severe WMAP Dark Matter constraints, while at the same time leaves almost unaffected the baryon density in agreement with primordial Nucleosynthesis.