MODELING MACROSCOPIC AND BABY UNIVERSES BY FUNDAMENTAL STRINGS

We develop a model of (1 + 1)-dimensional parent and baby universes as macroscopic and microscopic fundamental closed strings. We argue, on the basis of understanding of strings from the point of view of target D-dimensional space-time, that processes involving baby universes/wor mholes not only induce c-number ''alpha-parameters'' in the (1 + 1)d a ction, but also lead to loss of quantum coherence for a (1 + 1)d obser ver in the parent universe.