Wormholes, a fluctuating cosmological constant and the Coleman mechanism

We show that in a two-dimensional model of quantum gravity the summation over all possible wormhole configurations leads to a kind of Coleman mechanism where the cosmological constant plays no role for large universes. Observers who are unable to observe the change in topology will naturally interpret the measurements of the size of the universe as being caused by a fluctuating cosmological constant, rather than fluctuating topology of spacetime. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

In a two-dimensional model of quantum gravity, the summation over all possible wormhole configurations leads to a Coleman mechanism in which the cosmological constant has no effect on large universes. Observers unable to observe changes in the topology will naturally interpret measurements of universe size as being caused by fluctuating cosmological constants rather than fluctuating spacetime topology.