We consider the evolution of the dilaton in a Friedmann-Robertson-Walker background by numerically integrating the equations of motion as determined by the low-energy expansion of the string theory action. We find that the dilaton may be fixed by either self-interaction terms providing a dilaton mass or decoupling in a radiation dominated Universe. We also comment on conditions applicable to an exponentially expanding phase.
Bibliographical noteFunding Information:
The work of KAO was supportedi n part by DOE grantD E-AC02-83ER40105a nd by a Presidential Young InvestigatorA ward. The work of NK was supported in part by the University of MinnesotaD octoral DissertationF ellowship.