ON THE DERIVATION OF THE STRING EFFECTIVE ACTION FROM AN ACCELERATION FIELD

We show that the string cosmology with dilaton can be derived, as a special case, from Caianiello's model of General Relativity with maximal acceleration interpreting the dilaton as an acceleration field. In fact Caianiello's theory allows us to recover the string-dilation effective action starting from a gravitational action which is minimally coupled to a scalar field by means of a particular conformal transformation of the Friedman-Robertson-Walker (FRW) metric. We show that this scheme works near the Planck scale where the pure string-dilaton dynamics works.