Modelling macroscopic and baby universes by fundamental strings Original Research Article

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/wormholes not only induce c-number “α-parameters” in the (1 + 1) d action, but also lead to loss of quantum coherence for a (1 + 1)d observer in the parent universe.