Modelling macroscopic and baby universes by fundamental strings

TL;DR

This paper models macroscopic and baby universes using fundamental strings, showing that baby universe processes induce parameters and cause quantum decoherence in the parent universe.

Contribution

It introduces a string-theoretic framework for understanding baby universes and wormholes, linking them to quantum coherence loss in a novel way.

Findings

Baby universe processes induce $ ext{$oldsymbol{ ext{c}}$}$-number parameters.

Such processes lead to loss of quantum coherence.

The model connects string theory with cosmological phenomena.

Abstract

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 "$\alpha$-parameters" in $(1+1)d$ action, but also lead to loss of quantum coherence for a $(1+1)d$ observer in the parent universe.