Non-critical String Cosmologies

TL;DR

Non-critical String Cosmologies propose an alternative to the Big Bang model, where dilaton-dependent terms influence universe evolution, leading to late acceleration and affecting dark matter relic densities.

Contribution

This work introduces non-critical string effects into cosmology, showing their impact on late acceleration and dark matter relic abundance calculations.

Findings

Late transition to acceleration at z=0.2

Dilaton effects relax WMAP dark matter constraints

Neutralino relic densities are diluted by factors of ten

Abstract

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 Universe\'s 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.