Relic dilatons in string cosmology
Abstract
Description
The allowed mass windows for a cosmic background of relic dilatons are estimated in the context of the pre-big bang scenario. The dilatons are produced from the quantum fluctuations of the vacuum, and the extension of the windows is controlled by the string mass scale. The possible relaxation of phenomenological bounds due to an intermediate stage of reheating is discussed. Even without such a relaxation, the allowed range of masses includes a light sector in which the dilatons are not yet decayed, and could provide the dominant contribution to the present large scale density.
13 pages, LATEX, two figures included using epsf. To appear in Proc. of the 12th It. Conf. on Gen. Rel. and Grav. Phys. (Rome, Sept. 1996), ed. by M. Bassan et al. (World Scientific, Singapore). An updated collection of papers on the pre-big-bang scenario in string cosmology is available at http://www.to.infn.it/teorici/gasperini/
13 pages, LATEX, two figures included using epsf. To appear in Proc. of the 12th It. Conf. on Gen. Rel. and Grav. Phys. (Rome, Sept. 1996), ed. by M. Bassan et al. (World Scientific, Singapore). An updated collection of papers on the pre-big-bang scenario in string cosmology is available at http://www.to.infn.it/teorici/gasperini/