On dilaton solutions of de Sitter inflation and primordial spin-torsion density fluctuations

Four classes of exact solutions of Einstein-Cartan dilatonic inflationary de Sitter cosmology are given. The first is obtained from the equation of state of massless dilaton instead of an unpolarized fermion fluid used previously by Gasperini. Repulsive gravity is found in the case where dilatons are constraint by the presence of spin-torsion effects. The second and third solutions represent respectively massive dilatons in the radiation era with the massive potential and torsion kinks and finally the dust of spinning particles. Primordial spin-density fluctuations are also computed based on Primordial fluctuations of temperature obtained from COBE data. The temperature fluctuation can also be computed from the nearly flat spectrum of the gravitational waves produced during inflation and by the result that the dilaton mass would be proportional to the Hubble constant. This result agrees with the COBE data. This idea is also used to compute the spin-torsion density in the inflation era.